Transformable: Fix bug related to local references
TrueTypeFont: Move TTF initialization to nom::init

* Rename nomlib_init function to init

This hopefully fixes the long-standing de-initialization issue with
TTF_Quit happening too early…
SDL_helpers: Introduce save_png function
Image: Remove colorkey argument from init variant
Image: Introduce methods for initializing from a) dimensions; b) SDL_Surface
Image: Add additional err checks to save_[bmp|png] methods
Bit of code clean up
Pixel: Disable compiling & inclusion of class

* This class is probably on the cut list…
RendererInfo: Refactor a bit

Fix Issue #6
Texture: Introduce methods — maximum_size & optimal_pixel_format

See Issue #6
Rect: Fix a typo (rhs.lhs) & fix indention
Texture, Image: Introduce set_pixel method & clean up pixel method & docs
Image:: Relocation of draw method from Window to Image class
Pixel: Removal of class

* nom::Image is our interface to replace this class
Glyph: Introduce operator overloads

* I was planning on using these overloads for std::sort, but no can do
with std::map (sorted by key).
Image, Texture: Fix for incorrect pixels cast in 32-bit bpp
TrueTypeFont: Initial overhaul refactoring - separation of font from text
system/clock: Rename getCurrentTime to time
Introduce stub files for eventual SDL_Log integration
TrueTypeFont: Additional clean up work