GNOME HIG compliance improvements

There are a number of cosmetic changes that should be made to make BloGTK follow the GNOME Human Interface Guidelines much more closely. Link to current HIG version - http://library.gnome.org/devel/hig-book/2.30/

http://library.gnome.org/devel/hig-book/2.30/desktop-application-menu.html.en#menu-item-functional-description
- don't put the version number in the .desktop entry menu text
- don't include technical information "GTK" in the menu text or tooltip
- do include useful name e.g. BloGTK Weblog Client

http://library.gnome.org/devel/hig-book/2.30/windows-properties.html.en#window-props-titles
- don't include the version number in the window name

http://library.gnome.org/devel/hig-book/2.30/menus-standard.html.en
- have a Preferences item in the Edit menu rather than Edit Settings
- then remove app name from Preferences dialog (and edit entry dialog, etc)
- fairly unusual to have an accelerator key on the About menu entry? NB there is no accelerator on the About entry for the Edit post window, which is inconsistent

http://library.gnome.org/devel/hig-book/2.30/toolbars-appearance.html.en
- enable toolbars to be switched off
- enable toolbars not to have text labels

Just a starter, no time for a full review right now.