Blender Git Commit Log

Zoom to frame options, requested by the Hwoozeberry (dutch translation)
team.

There are 3 options here:

1) Keep range (previous behaviour)
2) Seconds - allows a specified offset in seconds around current frame
3) keyframes - zoom to include a number of keyframes around the cursor

Options 2 and 3 have their own properties to tweak the behaviour and all
options can be found in User Preferences->Interface under the 2D
viewports section.

Number 3 will probably need some refinement so commiting here for the
hwoozeberry team to test first.