Rstview

--------------------------

* Added a configuration registry and use it instead of directly getting/setting configurations from ``settings.RSTVIEW_PARSER_FILTER_SETTINGS``;
* Now configurations can be added/updated/removed per application through registry interface;
* Now ``settings.RSTVIEW_PARSER_FILTER_SETTINGS`` is only used as a startup configuration sets that are not needed to be tampered anymore;
* Added discovering methods to discover configuration files from enabled applications;
* Added tests for registry and discovering;
* Updated documentation to include configuration registry and all;
* Removed some unused settings:

* ``RSTVIEW_PARSER_ENABLE_FILE_INSERTION``;
* ``RSTVIEW_PARSER_ENABLE_RAW_INSERTION``;
* ``RSTVIEW_PARSER_LANGUAGE_CODE``.

--------------------------

* Fixed tests settings and conftest so tests can run correctly through tox;
* Added Django 1.7, Django 1.8, Django 1.9 support since these versions have passed tests through tox;

--------------------------

* First try to use tox for tests;

--------------------------

* Added unittests with Py.test and a dummy project for tests;
* Added better documentation using Sphinx+Autodoc+Napoleon;
* Now require for Django==1.8;
* **Major changes** in modules and structure:

* ``rstview.parser`` has been refactored to contain everything in two classes;
* Improved view ``rstview.views.RSTFileView`` to be more flexible;
* Default shipped view template now inherits from ``skeleton.html`` instead of ``base.html``;
* Template filter ``source_render`` has been dropped in profit of template tag ``rst_render`` which has more options;
* Dropped old sample ``rstview/rst_sample.rst``;
* ``rstview.views.RSTFileView`` now raise an exception if ``doc_path`` attributed is empty;

--------------------------

Minor update for README.

--------------------------

* Added ``source_render`` template filter;
* Updated README;