add hattach call to co_tree_insert
fixed a bug with checking co_tree_delete
optimized test set up
added update object test
reordered tests in TreeDelete()
added tests to confirm deletions in TreeDelete()
cleaned up spacing and indentations
added insert_force tests to InsertObj
reinitialized TestString1 in InsertTest
did stuff
Revert "did stuff"

This reverts commit 98fab8bb305dcb87732fbc3b8b854d349b7ab923.
Revert "fixed a bug with checking co_tree_delete"

This reverts commit 4a6ed39b0c8c95addad06724e9e7fba04269112c.
Fix tree length error checking.
Merge branch 'unit-tests'