Clean up code a bit; remove phased out IFont code fragments
Add timestamp to NOM_DUMP macro
Move DEFAULT_FONT_SIZE const var to types.hpp from Font.hpp
Initial integration of font cache into GUI examples
PlatformSettings: Introduce get_system_color method

* Introduce SystemColorType enum (method argument).
Clean up header files of BitmapFont & TrueTypeFont
Introduce getters & setters for font style (bold, italic, underline)

(Implemented only in TrueType).

* examples/fonts: Make second TrueType label bold.
* Text: Make update method part of the public interface.
CMakeLists: Disable un-necessary builds
Make default point size 14 in Text & TrueTypeFont interfaces