Moves http.Body to conversation.Body.
Adds BaseRequest, BaseResponse, BaseClient.
engine.py: Adds back Statistics concern.

processor.py: WebProcessorSession uses keyword arguments.

engine,processor.py: Adds more docstrings.
Configs docs to be cleaner. Adds docs on scripting hooks.

Changes api.rst to only show documented members.
Moves document.{HTMLScraper,CSSScraper} to scraper module.
Splits the api docs into seperate file for each module.

Adds more detail to docstrings.
Updates changelog title to 0.12.
Bumps version to 0.12.

Merge branch 'develop'

Conflicts:
	wpull/version.py