Bug 69315 - cs timestamp not supported

cswiki uses the  21. 5. 2014, 17:07 (UTC) timestamp.

Once month is matched, days from 1-12 are wiped out by
last_match_and_replace().
Changed last_match_and_replace() to replace only the first N-2 and
the last match, leaving the N-1 as day candidate.

Modified also:
- fixed a bug in monthR regex: if month name contains a dot, it needs to
be escaped. It happened e.g. on wikipedia:no.
Also raise Keyerror exception that was masking this bug.

- regex for day to include the dot (not mandatory but
improves robustness of the search).

- aligned names of self.timeznR->ptimeznR and self.yearR->pyearR for
consistency with naming convention.

- fixed a pep8 error at line 859

Change-Id: Ifee1041cf9762f419c48fc6cb0faa56b84d0bee4
Merge "Bug 69315 - cs timestamp not supported"