Added cleanup tasks to to-do list
Deleted timer.h

timer.c has long been gone. It's time we finally completely detach
ourselves from it
Removed some commented code

Nothing super worthwhile here
Consolidated swingFor(ticks) functions

swingLeftFor() and swingRightFor() should now both be accessed as
swingFor(). The functionality has remained the same.
Clean up movement.c and header

--Moved/added/edited/removed explanatory comments
--Moved order of functions around to make more sense
--Completely deleted deprecated functions
--Edited header to reflect the above changes