Framerate can now be specified in hundreths of a frame per second.

There's a bug, at least on my machine, where you can't edit the text directly, but must use the +/- buttons to adjust it (which is tiresome).

Related to issue #1.
Save and load framerate from files.

Observe file opening to update framerate in UI.

This commit fixes #1.
Merge branch 'xdna-fileformat'

Conflicts:
	gui/animationwindow.py