starting with refactoring of node generators
adding node generator and tests
continue with node generator
manual merge
refactoring to node_generator
adapting tests for node_generator refactoring
introducing max arity as template argument in basic tree, bug fixing assignment of intrusive node, small refactring artificial ramp
enable prog3 in artificial ant
Merge branch 'master' of https://github.com/Ambrosys/gpcxx into gerard/example

Conflicts:
	examples/artificial_ant/ant_simulation_nodes.hpp
	examples/artificial_ant/artificial_ant_main.cpp
	include/gpcxx/tree/basic_named_intrusive_node.hpp
Bugfixing and Refactoring