Merge pull request #5 from Sleaker/master

some minor fixes
Only mipmap when requested
Addes new features, see description

Added Screenshots (GLUtil.takeScreenshot())
Update Texture to use GL_CLAMP_TO_EDGE because GL_CLAMP was removed in
GL 3.1
Mat4.makeTranslation/Rotation/Scale for more effecienct matrices
FontRenderer.createMeshBatch() which uses the FontRenderer's shader
TextMesh.setPositon/getPosition do things
Fix comment on GLUtil (doesnt ALWAYS use back buffer) see glReadBuffer
add TextMeshBatch to only bind the font's texture once.
ShaderProgram.varMap is no longer static, fix bugs with multiple programs using the same names

Add Vec4.toRGBA
Remove SpriteBatch since it doesnt really do anything
Remove unused import from FontRenderer
Discard fragments if alpha = 0
use lwjgl 2.9.0 asit has j7 fixes.

Signed-off-by: Nick Minkler <sleaker@gmail.com>