Code styling (PEP8) for twitter.py

This is cosmetic commit. But I changed a few things about syntax:
_(in new code lines 603-628, 1363-1391, 1796-1806 and etc)_ I'm not sure what about old versions of python (I tested this in 2.5, 2.6, 2.7), but multiline expressions are allowed inside brackets without escaping EOL.

diff looks terrible, so it's better to see changed file in my fork.

This commit version successfully passes every test (except one because of [this](https://github.com/bear/python-twitter/commit/500d367e51ec64d1c5ae2f877c46971a7e361fc7) commit. I have a fix for it, but not sure if can attach it to this ticket).