revset: make matching() work on python 2.4
tuple.index() was apparently added to python 2.6:
http://bugs.python.org/issue1696444
Also remove a trailing comma to make check-code.py happy.
revset: use list instead of tuple for compatibility with python before 2.6
'string elements'.split() instead of explicitly typing a list of strings is
used. This is done in other parts of Mercurial code, too.