fixing symb reg example and renaming it to symb_reg_basic_tree
adding symb reg to cmake
 * the dot file is now written to a file

Merge branch 'master' of https://github.com/Ambrosys/gpcxx into gerard/example

Conflicts:
	examples/CMakeLists.txt
	include/gpcxx/config_version.hpp
Work on Tutorial, no proofreading