Code submissions have continually suffered from formatting
inconsistencies that constantly have to be addressed. Using
clang-format simplifies this by making code formatting more consistent,
and allows automation of the code formatting so that maintainers can
focus more on the code itself instead of code formatting.
This commit adds a preview to the properties window for transitions.
The preview will play back the transition at the global transition
duration or the transitions fixed duration, between two private scenes
with an A and B label, and different background colors.