Using `misc/scripts/fix_headers.py` on all Godot files.
Some missing header guards were added, and the header inclusion order
was fixed in the Bullet module.
Due to memory contraints in other places in Godot it is unlikely that
anything higher than 1024 will actually work. When/if we improve memory
management for vectors we can increase this limit again
-Fixes to unwrapper (remove degenerates), makes Thekla not crash
-Added optional cancel button in EditorProgress
-Added function to force processing of events (needed for cancel button)
