renamed getUseAlphaChannel to isAlphaChannelUsed to fit with other "bool is*" getters
git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@657 dfc29bdd-3216-0410-991c-e03cc46cb475
Replaced some f64 by T in container classes, where computations were only f32 correct anyway.
Made triangle3d.isOnSameSide private as it is completely unrelated to triangles.
Renamed plane.existsInterSection to plane.existsIntersection since all other functions concerning intersections use the small s.
Fixed plane3d.classifyPointRelation to return the correct relation. Spotted by vitek.
git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@655 dfc29bdd-3216-0410-991c-e03cc46cb475