Tests: SBCL passes test-lisp and test-upgrade
Also:
* big refactoring of test infrastructure
* contrib/debug.lisp and (asdf/driver:asdf-debug) for debugging.
* remove aif and it, use the cleaner if-bind.
* backtrace support, with improvements from trivial-backtrace.
* integration of asdf-condition-control (originally from xcvb-driver)
* simplify the upgrade heuristic: always tries to upgrade once.
  The previous heuristic was too complex with too many failure cases.
  You are thus assumed to want a given version asdf
  if and only if it is in your source-registry.

The general-purpose support code is now
a bit less than 50% of the code in ASDF.

I had failed to preserve the extension point cleanup-upgraded-asdf,
reusing the name the wrong way. Doing it right this time.

Have a package-definition-form in defpackage format
rather than ad-hoc package-data.

Backtrace on clisp and ecl.

This notably includes the former xcvb-driver:run-program/,
a much better replacement for run-shell-command.
This also includes image initialization, dumping, quitting.

Also, tweak some tests some more.

Also, move wild-modules to a contrib/ directory.
Refactor tests somewhat, introducing a function touch-file.

Make default-directory a root pathname, remove it from source-registry.
Have it use lisp-implementation-directory.
Remove any attempt to use the "current directory".
Users who want that can still try to
	(pushnew '*default-pathname-defaults* asdf:*central-registry*)

Rename tmp/ to build/ and move asdf.lisp there. Update asdf.asd.
Rename implementation.lisp to compatibility.lisp.
Move *asdf-verbose* and asdf-message to upgrade.lisp

Avoids interspersed error output in CCL, or backtrace to terminal in SBCL.

Had to fix a few more issues in package update,
add support for frobbing CCL setf function names,
and fix upgrade detection for the new package world.

Fixed corner bugs in the package surgery.
Stopped using fmakunbound as part of the package definition;
it should happen as part of with-upgrade,
or, for now, systematically with defgeneric* and defun*.
Added special magic for ASDF fixup, that will have to be enhanced.

2.26.67: define-package looks good, BUT we need to somehow avoid unnecessary frobbing, as per *upgraded-p*.

New pathname functions to work around more logical-pathname issues.
See discussion with rpgoldman on asdf-devel, and see CCL ticket:953.
Also, tweak build to reflect recent refactoring of asdf.
WIP of define-package work needed for clean upgrade (still broken).

TODO: Create a define-package that can make it upgrade itself.

ECL output-files semantics has changed, so unintern the old one rather than conflict.
Rename *compile-op-compile-file-function* to just *compile-file-function*.
Factor all the lisp build perform's through perform-lisp-FOO,
so they can be shared with concatenated targets that are not cl-source-file
without fighting default methods and class inheritance.

Add its forgotten source file test/lambda.lisp. Oops.
Skip one of its tests that mysteriously breaks on ECL_bytecodes.

Bug identified by avodonosov.

The TRAVERSE issue makes it easier for user code to override TRAVERSE:
don't include FORCE FORCE-NOT VERBOSE in mandatory keyword arguments
for all methods. A method is notably provided by buildapp.

The bug in VISIT-DEPENDENCIES was causing IF-FEATURE'ed out
components to flag whoever depended on them as requiring to be rebuilt.
This notably caused a legacy SB-ROTATE-BYTE to always want to rebuild.
The dependency visit is now predicated on VALID-ACTION-P,
which requires VISIT-DEPENDENCIES to take an additional PLAN argument.

Also, use .all-systems rather than .system-and-dependencies as suffix for monolithic bundle ops.

Frob CLOS methods so &allow-other-keys.
This makes POIU happy, and probably GBBopen, too.

Also, fix make-pathname* to make CLISP happy.
Uniformly use "backward-compat*" in comments.
Rename operation-forced{,-not}-p to action-forced-p.
Shuffle some functions around.
Refactor operate into an :around and a regular method.