Quickcheck

short answer: withdraw all r*-related tests.
test passed both on ccl 1.9 x86, SBCL 1.1.12.11-a566e33 .

Main change:
1: the amount of test cases are vastly increased.
Each test insert 200 (or 600) elements into the tree and run a test 200 times.
In each test every elements are newly created.

2: added a test `:insert'. Until the test passes with R*-tree, it should be noted `unstable'.