Keys and mouse reference update for 0.92

Follow-up to https://answers.launchpad.net/inkscape-docs/+question/268871

The current Keys and mouse reference shows some errors and inaccuracies that need to be fixed in the next Inkscape version:

REMAINING:
==========

===== 1. Introduction =====
1.3. Don't forget to update when mailing lists are moved.

==== 4. Object ====
4.1. [Needs investigation, could well be a bug] Clipboard. Remove "shapes" in "This applies the path effect of the copied path to the paths/shapes in current selection.".

==== 6. Node tool ====
6.1.a Grow/shrink node selection.
NEW: PgUp/PgDown and Ctrl+PgUp/PgDown don't work for me - bug?

Intentionally not changed: 6.3. [To be confirmed] Scale nodes and Rotate nodes. In:
"If mouse is over a node, that node becomes the axis of scaling; otherwise it scales around geometric center of selected nodes." "If mouse is over a node, that node becomes the axis of rotation; otherwise it rotates around geometric center of selected nodes."
Replace "axis" with "center".

///// Known issues affecting the K&M reference /////

- Bug # #669162 "Stamping tool does not work with node tool in version 0.48"
- In Node tool > Delete, create, duplicate, "Alt +Del delete segment between two non-endpoint nodes", The command works with Backspace, but not with Del. If it's not a bug, then replace Del with Backspace in the reference.
- When creating a flowed text frame, you can only access the lower right one handle. But after the frame has been resized once, other unexpected handles (from the rectangle tool) show.

============================

DONE (patch file):

===== 1. Introduction =====
✓ 1.1. Add a note that depending on the keyboard some shortcuts may not work, but that most of them can be set in the shortcut editor.
✓ 1.2. Replace "RFE" with "feature request".

==== 2. Controls bar ====
✓ 2.1. Replace "Controls bar" with "Tool controls bar".

==== 3. Canvas > Guides, grids, snapping ====
✓ 3.1. Replace:
"toggle guides and snapping to guides"
"When you create a new guide by dragging off the ruler, guide visibility and snapping are turned on."
"toggle grids and snapping to grids."
"If you want to see the grids but not snap to them, use the global snapping toggle (% key)."
The commands no longer activate snapping (as of 0.47).

==== 4. Object ====
✓ 4.2. Bitmap. Modify "This exports the selected object(s) (all other objects hidden) as PNG in the document's directory and imports it back." ("imported back as embedded bitmap.").

==== 5. Selector ====
✓ 5.1. Move (mouse) (also affects Pencil tool). Replace "This temporarily disables snapping to grid or guides when you are dragging with grid or guides on." with "This temporarily disables snapping when you are dragging with snapping activated".
✓ 5.2 Scale (keyboard) (also affects Node tool > Scale nodes). Add an example to clarify "Scaling is uniform around the center, so that the size increment applies to the larger of the two dimensions."
✓ 5.3 Rotate around opposite angle: In rotate mode, if you hold Shift and drag on a rotation handle, the opposite angle of the object's bounding box becomes the center of rotation. This info is missing currently.

==== 6. Node tool ====
✓ 6.1. Grow/shrink node selection. In:
"Each key press or wheel click selects the nearest unselected node or deselects the farthest selected node.",
"wheel click" should be replaced with "wheel turn".

✓ 6.2. Move nodes (mouse) and Move node handle (mouse). In "This restricts movement to the directions of the node's handles, their continuations and perpendiculars (total 8 snaps)." and "The default angle step is 15 degrees. This also snaps to the handle's original angle, its continuation and perpendiculars.", replace "continuation" with "opposite direction" or "counter direction".
✓ 6.4. Add node. Replace "Click + Click" with "Double-click". (Also affects other parts of the reference.)

==== 7. Tweak tool ====
✓ 7.1. Operation. In "Ctrl +mouse drag act temporarily switching to shrink mode" and "Shift + Ctrl +mouse drag act temporarily switching to grow mode", replace "act temporarily switching" with "temporarily switch".

==== 8. Measure tool ====
✓ 8.1. Replace "set the measure base to the cursor" with "set base of angle measurement to cursor position".

==== 9. Rectangle tool and Ellipse tool ====
✓ 9.1. Draw. Replace "This restricts rectangle so its height/width ratio is a whole number." and "This restricts ellipse so its height/width ratio is a whole number." with "This restricts width/height ratio or its inverse to a whole number or the golden ratio.".

==== 10. Pencil tool ====
✓ 10.1. [To be confirmed] In "If a path is selected, Shift+clicking anywhere starts a new subpath instead of a new independent path.", add details on Shift+Drag.
✓ 10.2. [To be confirmed] Info about click with Pencil tool is missing entirely (create lines). Add "Click -> start a straight line (finish with another click).".

==== 11. Pen (Bezier) tool ====
✓ 11.1. Finish, Cancel (also affects the Calligraphy tool). In "finish current line", "cancel current line", "erase last segment of current line" and "draw a calligraphic line", replace "line" with "path". EDIT: replaced with 'stroke' for calligraphy tool, as that talks about a calligraphic stroke.
✓ 11.2. [To be confirmed] Finish. Replace "Enter, right click, or double left click finish the current line, discarding the last unfinished (red) segment.", with "Enter or right click finish the current line, discarding the last unfinished (red) segment. Double left click finishes the current line where double-clicked.".

==== 12. Text tool ====
✓ 12.1. Navigate in text. Replace "Use them with Shift to extend selection instead." with "Use them with Shift to extend or reduce selection instead.".

==== 13. Gradient tool ====
✓ 13.1. Gradient editor. Remove the section (the gradient editor was removed in 0.91).
✓ 13.2. Create/delete intermediate stops. Replace "This adds new stop(s) in the middle(s) of selected segment(s), so it requires that more than two adjacent handles be selected." with "This adds new stop(s) in the middle(s) between adjacent, selected stops or, if only one stop is selected, in the middle of the segment that starts with the selected stop.".

==== 14. Eraser, Spray and Tweak tools ====
✓ 14.1. Replace "set <tool name> width to 1 / 100" with "set <tool name> width to its minimum or maximum".

==== 15. Paint bucket ====
✓ 15.1. Replace "fill from each point same as initial point" with "fill from each point similar to the initial point"

==== 16. Dialogs ====
✓ 16.1. Document properties. Replace "Document preferences" with "Document properties" (Shift+Ctrl+D)