major overall improvements

improved the way BaseClass places glyphs on resulting texture
added some missing class access methods
added template driven setColor method
added some more nullptr guards
organised some fieds into FontTexture struct (a class soon?)
changed texture filtering from linear to nearest
	(anyway, who is scaling text? Just increase font size...)
added drawing of some font describing primitives (origin, bounds, startpoint)
temporarily added glyph bitmap shadows for debugging reasons (12.5%)
changed stored TrueTypeFont to shared_ptr for convenience and security
rebased derived classes to normal strings for now, less hassle
updated tech-demo elements, by default draws all font descriptors