refs #220 - Updated docs for rapidsms.contrib.handlers
refs #220 - PEP8 style changes for rapidsms.contrib.handlers
refs #220 - Additional tests for rapidsms.contrib.handlers
Context manager now deletes settings that did not previously exist
The default value, None, was a valid (but unintended) setting for some settings.
refs #220 - Updated rapidsms.contrib.handlers docs
Based on comments from @dpoirier.
refs #220 - Moved app start logic to __init__
Since the start() method is being deprecated.
refs #220 - Raise an error when pattern/keyword is not defined
refs #220 - Fixed implementation of INCLUDED_HANDLERS
And other small fixes to handlers utils.
refs #220 - Updated KeywordHandler example
refs #220 - Raise error when INSTALLED_HANDLER cannot be matched
refs #220 - Added missing section labels to docs
refs #220 - Removed extra line from docs
refs #220 - Updated PatternHandler note
In response to comments from @copelco.
Merge branch 'master' of github.com:rapidsms/rapidsms into docs/contrib/handlers
Revert "refs #220 - Raise error when INSTALLED_HANDLER cannot be matched"

This reverts commit 49005bfc60c617c45b48ec6a4a58ad4d00dee85d.
refs #220 - Updated docs in response to comments from @copelco
Imported handlers in __init__ for convenience
Merge pull request #248 from caktus/docs/contrib/handlers

refs #220 - Tests and docs for rapidsms.contrib.handlers