Add $_memeq, $_regex, $_streq, $_strlen convenience functions.

	Add $_memeq, $_regex, $_streq, $_strlen convenience functions.
	* NEWS: Document them.
	* data-directory/Makefile.in (PYTHON_FILES): Add function/__init__.py,
	function/strfns.py.
	* python/py-type.c (typy_array_1): New function.
	(typy_array): Call it.
	(typy_vector): New function.
	(type_object_methods): Add "vector".
	* python/lib/gdb/function/__init__.py: New file.
	* python/lib/gdb/function/strfns.py: New file.

	doc/
	* gdb.texinfo (Convenience Funs): New node.
	(Types In Python): Document Type.vector.

	testsuite/
	* gdb.python/py-strfns.c: New file.
	* gdb.python/py-strfns.exp: New file.
	* gdb.python/py-type.exp (test_fields): Add vector tests.