- construct on first use
- allows for faster map loading and unloading of xml loading tree
- modified expression and transform grammars to not take args/not crash
- simplifies interfaces, allows fast parsing from python without passing grammar instance
Dropped color_factory class in favor of single color_parser function. Moved implementation to new color_factory.cpp since it is odd to have two headers (color.hpp, color_factory.hpp) and only one source file.
