Cleanup explanations of options in bridgedb.conf.
Fix with combined with os.open; doesn't work on Python2.6.
Add logging to crypto module.
Merge branch 'feature/cleanup-config' into develop
Handle GPGME errors better in the EmailServer.

 * CHANGE getGPGContext() function to output at least some useful information
   when it encounters an error, rather than just spewing 'Unusable GPG Key'
   without any context.
Add better error handling if we cannot reach the Recaptcha server.
Fix the parsing of Accept-Language to actually support fallbacks.

All right. Going through the most significant bugs in this function:

 * The line from the original function:
     ``langs = request.getHeader('accept-language').split(',')``
   getHeader() returns ``None`` if the header isn't present, so this results
   in a TypeError on the split().

 * The line from the original function:
     ``langs = filter(lambda x: re.match('^[a-z\-]{1,5}', x), langs)``
   This chucks locales with capital letters, and doesn't much at all to insure
   that we're actually getting a well-formed header, all at the expense of a
   (rather expensive; they're slow in Python) regex call.

 * These lines from the original:
       # add fallback languages
       langs_only = filter(lambda x: '-' in x, langs)
       langs.extend(map(lambda x: x.split('-')[0], langs_only))
   If my 'Accept-Language' header starts with 'en-GB,en-US;q=0.92[…]', then
   this would add ['en','en'] to the end of my header, without even checking
   if I already have 'en'. Instead, we should check if 'en' is already there,
   and iff not, then add it *after the other English headers*. Not after
   Mandarin, Japanese, Arabic, Russian, and the other slew of languages that I
   half-assedly learned at some point.

 * These lines from the original:
       # gettext wants _, not -
       map(lambda x: x.replace('-', '_'), langs)
   Great. A pretty mapping. Good thing the returned values weren't saved as
   anything; otherwise they might have been useful!

 * Lastly, the way that languages, once parsed were added to gettext, would
   raise UnhandledErrors, *and* it didn't even add the fallbacks correctly,
   meaning we could only get one language at a time.
Update .gitignore to exclude log files even in the top-level dir.
Update gen_bridge_descriptors docstrings, add TODO note on making NTOR keys.