PEP 8 Compliance

Hey,

This pull request is for changes that bring your Forecast.io module up to PEP 8 standards. This did require renaming all of the functions in the module, but I simply turned the old functions in to deprecated wrappers that people should stop using now.

There were also some changes made to the code, such as using string formatters. I noticed you were still looking for simplejson so I assumed you were trying to keep backwards compatibility with non-modern Python (<2.6) so I made sure to use string formatters that should be compatible.

Here is my primary commit message:

```
Made modifications to the files to make them compliant with Python's PEP 8:

- http://www.python.org/dev/peps/pep-0008/

As part of this some of the functions were renamed to use a lowercase-
underscore format instead of camelCase. The camelCase functions were
simply made deprecated wrappers for the real functions. As a note, the wrapper
functions do throw a 'DeprecationWarning' when called.

The docs were also updated to the new function names as well.
```

-Tim