Update debugger button states at startup to disable non-functional JIT menu entries
Add an IsMovieActive function.

Makes things a bit simpler, since this is a common check.
Merge pull request #1014 from RachelBryk/active-movie

Add an IsMovieActive function.
Merge pull request #1015 from zhuowei/update_debugger_menu_at_startup

Update debugger button states at startup to disable non-functional JIT menu items