dwiki-scgi.py: update --idle-timeout's help message to be correct
httpcore.py: remove old commented-out code

It's been there too long. It's time for it to go.
comments.py: more spammers on Wandering Thoughts

Someday I will have a scalable solution to this. Probably it will involve
patterns in a file.
pageranges.py: don't match clearly bad months or days

Previously, a request for a DWiki url like '.../2012/99/' would be
considered as a year+month request and then blow up with an exception
inside the calendar module (because '99' is in no way a valid month).
Now we exclude clearly invalid months or days so that URLs with them
are not considered to be dates/date ranges at all.
netblock: update to latest upstream subproject

The upstream update is for modernizing the Python usage. The minimum
Python version is now believed to be 2.6+.