Implemented wrapper for ir_node, untested
Improved Node wrapper, introduced Tarval wrapper. Used in ConstantFolder::optimizePhi and updateTarvalForArithmeticNode, seems to work so far.
Improved wrapper and fixed bugs
Merge branch 'dev' of https://github.com/djrieger/mjplusplus into dev

Conflicts:
	src/firm_interface/ConstantFolder.cpp