first commit for ch12 Binary Search Tree
 On branch ch12
	new file:   ch12/README
	new file:   ch12/ch12.pro
	new file:   ch12/main.cpp
added node
	new file:   ch12/node.hpp
 On branch ch12
	new file:   ch12/binary_search_tree.h not tested yet
refact insert method based on CLRS
 On branch ch12
 On branch ch12
	renamed:    ch12/binary_search_tree.h -> ch12/binary_search_tree.hpp
	modified:   ch12/ch12.pro
Update README