internal/Graphics: Fix gcc compile issues
test/font: Fix GLSL version issue
Stamp: Add further documentation
Decode: Internal stbi io callbacks now static

To protect them; make visible only in Decode translation unit
internal/Graphics: Prefix methods with _

To clarify code; all methods prefixed by _ will be internal-only API
internal/Utility: Internal utility methods prefixed with _
internal/Debug: Methods prefixed with _
internal/Utility: Contains PlatformSystemInfo (now prefixed with _)
Makefile: Build tests/examples OFF by default
Merge branch 'develop-0.1.x' into develop-0.2.0
CompositeTexture: Add documentation
GlyphLibrary: Update class description
GlyphMap: Update class description
GlyphMap: Inline Bind/Unbind overloads
Viewport: Add documentation
Viewport: Update class description
Geometry: Fix compiler warning (NULL arithmetic)
Line: Add TranslateStart/End methods
Line: Add GetStart/EndPosition methods
Geometry: Add GetNumPoints method