Allow user to specify lisps for upgrade separately from lisps for test.

Added ASDF_UPGRADE_TEST_LISPS environment variable and ulisps local
variable.
Merge branch 'master' of ssh://common-lisp.net/project/asdf/public_html/asdf
Fix test-systed-asdf on Windows (hopefully).
More test cleanups: use assert-compare and assert-equal some more.
Add UIOP to the use-list of ASDF-USER, after testing in cl-test-grid.
Emit an error in an unhandled corner case of run-program.
Bump version to 3.1.0.71