Settle on "restore-image" and "dump-image" for our API names.
Unbreak match-condition-p and move it to utility,
give static scoping to the generic muffler,
rename the compiler and loader mufflers.
Fix with-input.
Remove crud from script-support.

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.

Remove debugging code from previous commit.

Also, use coerce-pathname in asdf-ecl and deprecate merge-component-name-type.

* fix sysdef-find-asdf (bug found by Attila Lendvai). Test case added.
* make compile-file* nicer wrt *compile-file-{failure|warnings}-behaviour*
 test case thanks to Stas Boukarev (lp#598018) + working around CLISP bug.
* allow for (setf (find-class asdf::foo) ...) to work more portably,
 to make cffi-grovel happy.