Revert "last typos"

This reverts commit 0af57f740aba40296bcb8c5dcfc08796b21fc8c1.
Revert "oops"

This reverts commit dc46348a6671b87199400d6b68e27fbcd736f27e.
Revert "S3O: upload vertices/normals/texcoors separately"

This reverts commit cb220bd2ae65b9e6d2df0e9ebb571fbca8727451.
use interleaved VBOs
1. sorry for the reverts but the commits where conflicting too much with my changes
2. interleaved VBOs are preferred in OpenGL -> they are much faster and easier to manage
3. my solution merges VBO & VertexArray rendering in one code and has runtime check if VBOs are supported at all

Again sorry, normally I dislike reverts (esp. after such revert fights), still in this case my changes really make sense and are worth it.
add float3 test
fix grass shadow
grass shadowgen code is added too but disabled (it looks strange)
fix compile error regarding double used VBO for class & enum