match: let regex match function return a boolean Match function for regex pattern kind is built through _buildregexmatch() and _buildmatch() using _rematcher() that returns a re.match function, which either returns a match object or None. This does not conform to Mercurial's matcher interface for __call__() or exact(), which are expected to return a boolean value. We fix this by building a lambda around _rematcher() in _buildregexmatch(). Accordingly, we update doctest examples to remove bool() calls that are now useless.

match: make arguments of _expandsets() optional Arguments 'ctx', 'listsubrepos' and 'badfn' are optional in function body.

match: make _donormalize's auditor and warn arguments optional Argument 'warn' is actually non-required, since there's a 'if warn:' check before usage. Argument 'auditor' is passed to pathutil.canonpath(), in which it is optional.

match: add doctest examples in match() Make the docstring raw, as it now includes escape characters.