Renames updateFkey() to updateChatFkey()

I found this a bit confusing when reading the code, because we
are also working with the sites' fkeys, but this function isn't related
to that.
Expands .gitignore log pattern to include time-rotated files.

The .gitignore file I applied a few commits ago (the one provided by
GitHub, which included patterns for some files that were being generated
by setup.py) did not include this pattern, and log files were showing up.
Merge pull request #10 from jeremybanks/master

Renames updateFkey() to updateChatFkey()