Reworked the document generator and introspectors to work with 2.4.0.
This commit also includes a moving away from one mayor BaseIntrospector into DocumentationGenerator, BaseIntrospector and BaseMethodIntrospector (and there respective ApiView and ViewSet parts).
The ViewSet part has been updated to use `func_code.co_freevars` and `func_closure` for better detection of `@action` and the new `@list_route` (introduced in https://github.com/tomchristie/django-rest-framework/blob/2.4.0/rest_framework/decorators.py).
Removed some unused code.
DocumentationGenerator now uses generate to generate both models and operations.
This is in preparation for the DocumentationParsers
Moved settings from __init__.py to settings.py and updated settings to use a object
Split doc block parsing into a configurable setting and more.
- Added RST like documentation parser
- Added deserializer, serializer, query, post options that can be provided by doc blocks
- Did some minor tweaks related to description etc.
RST like documentation parser - Added parameter variables
Added UrlParser configuration setting
Added some extra tests and tweaked `IntrospectorHelper.import_from_string`
Added rstLikeDocumentationParser tests
Introduced documentation formatters and some other minor changes.
Also:
 - [Global] Replaced `rest_framework_swagger` from imports and replaced it with `.`
 - [Settings] Added `DOCUMENTATION_FORMATTER`
 - [Settings] Renamed `DEFAULT_DOCUMENTATION_PARSER_CLASSES` to `DOCUMENTATION_PARSER`
 - [Settings] Renamed `DEFAULT_URL_PARSER_CLASSES` to `URL_PARSER`
Updated README
Added TravisCI configuration and fixed Python 3 issues

Signed-off-by: Warnar Boekkooi <warnar@cerbex.com>
Added alphabetical sort on the top level apis

Contains fork from WhiteDawn : Reworked swagger API Key to work with django-rest-framework's token authentication

Rework on the fork from lukas-hetzenecker : Group resources by url
Some apis we're removed whereas they shouldn't be removed
Merge remote-tracking branch 'origin/pr/54'

Conflicts:
	rest_framework_swagger/__init__.py
	rest_framework_swagger/views.py