Update src/dmise/ui/container.d

Change getSize to return a Coord
Update src/dmise/animation/animation.d
Update src/dmise/menu.d
Update src/dmise/ui/container.d
Merge branch 'hdon-branch' of github.com:ylegall/Dmise
Adds a basic container implementation.
fix errors in container
adds TODO tasks
adds unit tests to vector.d
add support for assignment operators on vectors
import math symbols
added oglconsole and animated gif support
added oglconsole and animated gif support
fixed bug in makefile
fixed bugs in texture loader, added basic gif frame demo to dmise.entity.PlayerShip
modest improvement to gif frame demo in dmise.entity.PlayerShip