Fixed call to random.randrange in random_vertex function.
Update live coding app without frame function.

Previously, if there was no defined frame function the scene would not
update until the mouse was moved within the vroom window. A workaround
for this was to define an empty frame function which would trigger the
update. This is no longer necessary.
Disable lighting by default.
Added watch list for live coding.

It is now possible to specify additional files which should trigger live
coding updates. Filenames are passed to the program using the --watch
argument.
Merge branch 'watch-list'
Added watch_list command line option.
Added support for gridded data.
Merge branch 'mesh'

Conflicts:
	bin/vroom