Changed 'core.setup()' so it sets them to reasonable defaults.
Tweaked how the "usage" string is generated: 'core' now provides
'gen_usage()', which is used instead of 'USAGE'.
Modified "build_py" and "sdist" commands to refer to
'self.distribution.script_name' rather than 'sys.argv[0]'.
Changed 'prune_file_list()' so it also prunes out RCS and CVS directories.
Added 'is_regex' parameter to 'select_pattern()', 'exclude_pattern()',
and 'translate_pattern()', so that you don't have to be constrained
by the simple shell-glob-like pattern language, and can escape into
full-blown regexes when needed. Currently this is only available
in code -- it's not exposed in the manifest template mini-language.
Added 'prune' option (controlled by --prune and --no-prune) to determine
whether we call 'prune_file_list()' or not -- it's true by default.
Fixed 'negative_opt' -- it was misnamed and not being seen by dist.py.
Added --no-defaults to the option table, so it's seen by FancyGetopt.
in the module of the command classes that have command-specific
help options. This lets us keep the principle of lazily importing
the ccompiler module, and also gets away from defining non-methods
at class level.
template into a new method 'prune_file_list()', called from
'get_file_list()' rather than 'read_manifest()' -- this keeps
'read_manifest()' more general.
Deleted the redundant call to 'exclude_pattern()' in 'make_distribution()'
-- this had the same intention as 'prune_file_list()', but was incomplete
(only pruned the release tree, not the build tree) and in the wrong
place (the prune wouldn't be reflected in the manifest file).
