Added new method ``Zepto\Zepto::url_for()``. Give it a filename, and it checks to see if it's a valid file in the 'content' directory and returns its' fully-formed URL
Merge branch 'develop' into feature/move-nav-gen-to-plugin
Added new ``Zepto\ZeptoTwigExtension`` to handle all the fun Twig functions and stuff.
Created new ``NavGenPlugin``
Renamed ``$container`` to ``$app`` inside ``Zepto\Zepto``
Added new method ``Zepto\Zepto::link_for()`` to generate HTML output for a link
Added new class ``Zepto\Helper`` to hold all helper methods, added ``link_for()`` and ``url_for()``  to it. Removed same methods from ``Zepto\Zepto``
Changed other references to ``$c`` or ``$container`` to ``$app``, following on from 490b695
Major cleanup for ``Zepto\Zepto``. Removed method ``create_nav_links()``, moved ``default_config()`` and ``validate_config()`` to ``Zepto\Helper`` and moved ``generate_nav_html()`` to ``NavGenPlugin``
Removed ``create_nav_links()`` method call from ``Zepto\Zepto::_construct()``
``$app['nav']`` in ``Zepto\Zepto`` is empty unless specifically set. This should probably be changed.
Updated test class for ``Zepto\Zepto`` and added new test class for ``Zepto\Helper``
Another change that should've been in 490b695
Updated test class for ``Zepto\Zepto``
Merge branch 'develop' into feature/move-nav-gen-to-plugin
Changed ``Zepto\ZeptoTwigExtension`` to ``Zepto\Extension\Twig``, updated ``Zepto\Zepto`` accordingly
``Zepto\Helper::url_for()`` now makes URLs end with a '/'. Also removed some dead code and updated test class.
Moved ``Zepto\Zepto::run_hook()`` calls to the constructor for readability.
Fucks sakes, mate
Added spacing to link markup in ``Zepto\Helper::link_for()`` and updated test class