Tweak two tests, for CLISP, ABCL.
Tweak some tests for ABCL.
Hush autoloading in clean-load test.
Better exit message for old ABCLs in test-encodings.
2.31.1: require-system, a class for systems that use (REQUIRE ...)

Based on a patch by Stelian Ionescu.
2.31.2: fix NIL to work as a "skip me" designator in component-depends-on.

Use it to test (:feature :sbcl (:require :sb-posix)) and such.
Better cleanup before upgrade test
Better output-translations during testing, particularly during upgrade.
2.31.3: ensure upgrade before find-system. Also tweak primary/secondary output.

If you let find-system inside with-system-definitions before you upgrade ASDF,
you might have bad surprises when you upgrade then a previous definition survives.
2.31.4: class name can be read from string.

add safe-read-from-string to support it.
2.31.5: Fix deferred-warnings on CCL. Fix old FEATURE broken by 2.31.2.

On CCL, we were trying to persist data that can't be written and read back
regarding the specializers of context function and values of arguments.
Now drop the information at the cost of slightly less precise warning messages.

In 2.31.2, we failed to export FEATURE from asdf/operation,
causing this compatibility feature to fail.
2.31.6: disable deferred warnings check by default, until a smooth upgrade solution is found.
2.31.7: Package issues.

Another pass package upgrade.
Export FEATURE from correct package.
Use package :asdf-user when reading file for version.
2.31.8: Intern require-system's.
2.31.9: rename ASDF/DRIVER to UIOP, keep old names as nicknames.
2.31.10: Fix some exports. Fix some tests. Documentation tweaks.
Fix upgrade test. Tweak other tests for uiop.
2.32: bless 2.31.10 as release.
Frob doc & TODO. Add tagged release extraction to run-test.
2.32.1: try to make upgrade smoother on old SBCL 1.0.40 with old ASDF 2.011.

Another issue with (setf output-translations).
2.32.2: make ECL upgrade less magic and more robust.

Tested with
make u l=ecl_bytecodes ASDF_UPGRADE_TEST_TAGS="2.26 2.31"
make u l=ecl ASDF_UPGRADE_TEST_TAGS="2.26 2.31"
Add a symlink to help with upgrade test from asdf 2.27-2.31