* 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

Move fake-release-directory to Lisp.
Fix enough-namestring in Makefile.

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.

allows full bootstrap of XCVB, including ironclad.
Disable nemk self-build from tests,
as there is no ASDF equivalent to :around-compile.
Also, fix a2x wrt latest ASDF's find-system and reuse of component objects.

* extract fasl type from target:
 at least lispworks depends on pathname type and its fasl type varies!
* rucksack not available on clisp (and needed fixes; see our xcvb repo of it)
* accept compile-file failure semantics of clisp
* suppress duplicate entries for a directory in the source-registry:
 The first one wins, with its recurse and exclude flags.
* fix hello and test/runme
* fix various option parsing mistakes

when emitting output so it looks nice on the screen.
Added much more instrumentation of what xcvb isdoing at verbosity 10.
Got rid of some commented out code we don't need.

	settings known to xcvb or the individual value of a single one.
Change the default object-directory location to be
	$HOME/.cache/xcvb/common-lisp/<lisp-implementation-version>/
Added format! in driver.lisp to help with debugging and forcing output.
Debugged CMUCL support in driver.
Fixed implementation-identifier support in extract-target-properties.
Allowed Makefile in example-1 to parameterize on lisp implementation.
Refactored how option-specs are specified for command line options.
Removed dead code paths from simple-build backend that dealt with
	"xcvb.mk" and the makefile output file.
Muffled warnings when loading asdf.
Added target-asdf-version setting which you can query with show-settings.
Started DONE.rest

character in the right place. This helps immensely when visually parsing the
output of a lot of executed computations.

Rename search-path to source-registry, registry to grain-registry.
Extract ASDF implementation identifier from target, so we may use it later.

Very portable, but serial support only, no parallel queueing for now.
Also, driver.lisp now has *fatal-conditions* like *uninteresting-conditions*
instead of *fatal-condition*.
Added support for driving all the current actively maintained CL implementations.

It now actually functions and runs the computations to produce
the fasl/cfasl files! I don't want to up the revision number since
the function SIMPLE-BUILD still needs cleaning up in relation to an
apparently meaningless :output keyword i nthe function's lambda-list,
among other things.

Fixed ALL-NEWER-PATHNAMES-P to additionally understand that when
output files do not exist, then the output file set can't possibly
be newer than the input set. We return NIL in this case which forces
the regeneration of the ouput files.

Added some comments for things we need to check later in the code.

Some minor code formatting changes.

TODO: need to better control the cwd vs *default-pathname-defaults*

Converted the makefile style transformation of a computation into
a command into a more generalized external command form of the
computations.  Condensed functionality from driver-commands.lisp and
makefile-backend.lisp into external-commands.lisp. This is because at
this time both the makefile backend and a new run-program back end will
use them.

Added a run-program based backend called "simple-build" which will execute
the commands necessary to build the dependencies in the graph. At this
time it is a serial execution of the dependencies. The functionality is
not yet complete and currently broken as of this checkin.

Fixed up the xcvb.asd file to denote the new dependencies.