Make sure we (re)initialize-asdf at some early point: things may have changed after image-dump.

Fix tests with SBCL, too.
Remove obsolete setup.lisp for good. We are in an asdf 2 world!

This allows the examples to be created without having to install
an XCVB. The primary implementation is in bootstrap.lisp and
additional code in driver.lisp.
+ The created XCVB is made with one of the supported lisp
implementations even though the enclosing lisp invocation might
not be.
+ Refactored lisp-invocation into its own package.
+ The cache-description file contains notes about how the cache
should function. The cache is both the multi-user cache as in
distcc, ccache, etc, but also the user specific workspace for
where to dump fasl files and whatnot.

rename *tmp-directory-pathname* to *temporary-directory*.

* Use define-command to define and register a command
* Introduce the notion of workspace to store intermediate and target files.
* Update Makefiles for new intended output paths

Fixes to the bridge and to CMUCL, ECL, SCL support that make it work better.

driver: fix back the allegro run-program after latest changes
tests: refactoring so xcvb-driver-test can be run independently
other: fix some missing renamings of escape-shell-token.

Try to make it work with gcl - but gcl fails to compile driver.lisp.