TextEngine

Added new event triggered before bliting each glyph bitmap

A new method TextRendering::TextLayoutStrategy::OnGlyphProcessing has been added which is triggered before bliting each glyph bitmap. Default implementation has been added to keep backwards compatibility. This offers the possibility to skip the bliting of a glyph bitmap if needed. For this, also the TextRendering::TextLayoutStrategy::Action enumeration has beed extended with a new Break value.