Fixed various MacPython-specific issues found by attempting to use the standard core setup.py for MacPython.

This module broke on the Mac (where it can't work, but distutils seems to import it anyway) because it imported pwd and grp. Moved the import to inside the routine where they're used.

XXX Why doesn't distutils on Windows use the same set of flags as Python?

The default implementation calls _compile() to compile individual
files.  This method must be implemented by the subclass.  This change
factors out most of the remaining common code in all the compilers
except mwerks.

Two new tests are needed:

Don't skip building an extension if any of the depends files are newer
than the target.

Pass ext.depends to compiler.compile() so that it can track individual
files.

Always use _setup_compile() to do the grunt work of processing
arguments, figuring out which files to compile, and emitting debug
messages for files that are up-to-date.

Use _get_cc_args() when possible.

This change is not backwards compatible.  If a compiler subclass
exists outside the distutils package, it may get called with the
unexpected keyword arg.  It's easy to extend that compiler by having
it ignore the argument, and not much harder to do the right thing.  If
this ends up being burdensome, we can change it before 2.3 final to
work harder at compatibility.

Also add _setup_compile() and _get_cc_args() helper functions that
factor out much of the boilerplate for each concrete compiler class.

Remove __init__ that just called base class __init__ with same args.
Fold long argument lists into fewer, shorter lines.
Remove parens in tuple unpacks.
Don't put multiple statements on one line with a semicolon.
In find_library_file() compute the library_filename() upfront.

Making the world better a little bit at a time <wink>.

depends is a list of files that the target depends, but aren't direct
sources of the target.  think .h files.

The specific warning is that clean didn't find a directory that should
be removed if it exists.

Fix a bunch of multiline string constants that used +.

Call ensure_string() with one arg too, since the second value passed
was the default.

Make all returns explicit and rearrange logic to avoid extra
indentation.

mode is not computed in dry_run mode, so it can't be included in the
log message.

Fixes a bug for Solaris pkgtool (bdist_pkgtool) that would have
prevented it from building subpackages.

constant.

This is a conservative version of SF patch 504889.  It uses the log
module instead of calling print in various places, and it ignores the
verbose argument passed to many functions and set as an attribute on
some objects.  Instead, it uses the verbosity set on the logger via
the command line.

The log module is now preferred over announce() and warn() methods
that exist only for backwards compatibility.

XXX This checkin changes a lot of modules that have no test suite and
aren't exercised by the Python build process.  It will need
substantial testing.

 # XXX this isn't used anywhere, and worse, it has the same name as a method
 # in Command with subtly different semantics.  (This one just has one
 # source -> one dest; that one has many sources -> one dest.)  Nuke it?

Yes.  Nuke it.

modules, distutils does not understand that the build version of the
source tree is needed.

This patch fixes distutils.sysconfig to understand that the running
Python is part of the build tree and needs to use the appropriate
"shape" of the tree. This does not assume anything about the current
directory, so can be used to build 3rd-party modules using Python's
build tree as well.

This is useful since it allows us to use a non-installed debug-mode
Python with 3rd-party modules for testing. It as the side-effect that
set_python_build() is no longer needed (the hack which was added to
allow distutils to be used to build the "standard" extension modules).

This closes SF patch #547734.