create tree
Merge branch 'shining' of https://github.com/wqfish/avl into shining

Conflicts:
	src/include.h
Merge branch 'shining' of https://github.com/wqfish/avl into shining
Merge branch 'shining' of https://github.com/wqfish/avl into shining

Conflicts:
	src/parser.y
Merge branch 'shining' of https://github.com/wqfish/avl into shining