Version 0.12.0

• Deprecate NE_ShadingEnable(). The name was misleading. All examples that
  use it have stopped calling it.
• For sprites, add a way to specify texture coordinates inside the material to
  use a small part of the texture instead of the whole texture:
  NE_SpriteSetMaterialCanvas(). This is now used in the sprites example.
• Stop using global variables in most examples. Instead, the rendering functions
  get values through the arguments of NE_ProcessArg() and
  NE_ProcessDualArg().
• Don't expect palette objects when loading GRF files if the file doesn't
  contain a palette.
• Allow loading BMFont fonts from RAM, not just nitroFS. Add an example of
  using rich text fonts from RAM.
• Added a function to reset the rich text font system. Also add a function to
  return the size that a specific text string would have if drawn.
• Add shadow volume example.
• Build some functions that do lots of multiplications as ARM to increase
  performance.
• Fix compilation with devkitARM.
• Fix linker invocation for C++ with BlocksDS.
• Update libDSF to version 0.1.2, with some speed improvements.
• Relicensed libDSF under "Zlib OR MIT" to simplify licensing with Nitro Engine.
• Some minor documentation improvements.