Added support for texture compression

Added support for texture compression. Currently Ericsson texture
compression (ETC1), AMD texture compression (ATC), and PowerVR texture
compression (PVRTC) are supported.

Helper methods are also included that allows ETC1 PKM textures to be
loaded with graceful fallback to uncompressed bitmapped texture.
Merge branch 'master' of https://github.com/MasDennis/Rajawali
Added S3(DXT1) texture compression

Adds support for DXT1 variant of S3 texture compression supported by
most Nvidia Tegra2 GPUs.
Added support for paletted textures

Added paletted texture compression as part of OpenGL ES extensions.
Renamed PaletteConfig to PaletteFormat for consistency with enums of
other compression types.
Added support for ATI 3Dc texture compression

Added ATI's 3Dc texture compression which adds great optimization for
compressing normal map textures. Always check hardware support before
using this type of texture compression.
Added dynamic ETC1 texture compression

Dynamically generates an ETC1 texture on-the-fly from an uncompressed
bitmap and adds it to the TextureManager instance.
Merge branch 'master' of https://github.com/MasDennis/Rajawali
Merge pull request #311 from AndrewJo/master

Texture compression support added