c: splitted binarytree stuff for proper testing
c/binarytest: proper prompts
c/binarytest: even better prompting routine
c/binarytree: added test-suite
c/test_binarytree: added test for second node
c/binarytree: lookup is public
c/test_binarytree: improved test second_node
c/binarytree: renamed functions to avoid collisions
c/binarytree: added some helper functions
c/binarytree: added prototype removal function
c/binarytree: expanded test 3 to check the whole tree