Geom changes

Turns out Haxe hates array access. Cool! Matrix, rectangle and vector
abstracts now wrap basic private types with fields instead. Did some
basic performance testing. It's a little faster tha flash.geom package
:) Cribbed the matrix multiplication code for the M33 from
flash.geom.Matrix as well, and removed dead fields. Also removed
Matrix22 and 44 until I have time to implement them properly. TBH looks
like I'll just crib and modify Matrix3D from flash.geom as well.