Effecient multicamera editing

Noting another feature request dmj726 made in #novacut.

Multicamera editing will be a first class feature in Novacut. There are 3 scenarios we need to accommodate:

1) Multiple cameras shooting the same shot simultaneously from different angles. As HDSLR cameras are so cheap by comparison, and as there is no film cost, it has become extremely common to shoot from multiple angles simultaneously. Despite requiring more equipment, this can reduce production costs as you can accomplish the same thing with fewer takes, less setup, less time... that is, if the editing workflow doesn't burn all the savings gained while shooting. This is also the simplest scenario and a place where we can automate a lot (because Novacut can automate some of the setup of multicam edits by utilizing metadata from cameras and a bit of user supplied information).

2) The above, but using slices from two or more different takes of the same multicam shot. We can still leverage a lot of automation here.

3) Pseudo multicam where cameras are repositioned into a new shot, but action is repeated as if done in one shot with all angles present. This is the least easy to automate as user needs to specify how the different shots combine into a single psedo-multicam shot. But after the setup, we want the workflow to be as easy as (1) or (2). The psedo-multicam shot might be assembled from a mixture of the takes at each camera position.

dmj726, we're all over this! Tara and I obsess about multicamera constantly! Thanks for the feedback!