Merge pull request #1557 from seanpaultaylor/next

Updated sample fonts which now have kerning.
Texture cube support
-General texture support for texture cubes
-DDS and PVR support for texture cubes
FrameBuffer::createScreenshot lets you choose the format (RGB or RGBA)
It is now possible to update texture data without manually working with the texture handle.

Filtered file selection of #1513 and #1528
Removed Texture::Type::TEXTURE_UNKNOWN
Merge pull request #1558 from rcmaniac25/helpful-additions-textureCube-v3

Added support for Texture Cubes
Fixed GL_ASSERTS to GP_ASSERTS