Fixed sending of command again. Also now make g and m codes appear in uppercase automatically.
data["print"] is now a boolean, so we don't need to check against valid_boolean_trues anymore but can use it directly instead

Fixes #317
Revamped the events slightly

Payload data can now be properly injected into event handlers such as command triggers. Added a couple of new events to use for update triggers to the frontend instead of custom code, further decoupling the application. Movie rendering now also causes a frontend notification.
Starting documentation based on Sphinx
Forgot to check in the new VERSION file
Fixed refresh of SD file list

Closes #326
Fixed api_access decorator
Started documenting OctoPrint's REST API
Added sphinx dependencies to requirements
Forgot to commit images
Added a very small intro to the docs
Some further API documentation
Deleting a file of course work via DELETE, not POST
Some more documentation
More documentation
Merge branch 'revampedEvents' into devel
WARNING: A lot of changes to the existing API and the event system.

This WILL break existing API clients and probably some event handlers too. I'm sorry for the disruptive changes, but I needed to rectify some decisions before they went too far utilized elsewhere to still be corrected.

 Basically this change completely removes the old API and switches it (same endpoint) with the new one, that's basically the existing AJAX API that the client uses, but way more RESTful and based on JSON (exception being the file upload).

 The event system has been revamped to carry more payload data (and in an extensible form as dictionary, to allow for later addition of attributes to single events), with the existing event listeners adjusted to also allow users to make use of this data in their consumers.

 Documentation has been greatly enhanced for the REST API (and is still being added to), the events will be documented here as well.
Fixed test (did not yet match new return value format)
More work on the API + documentation

Changed some endpoints again (removed "/control" path element) and made API spit out only raw data (e.g. seconds, millimeters, unix timestamps etc) instead of formatted versions. Modified frontend to take care of formatting this data itself.
Hopefully fixed the issue where the /printer/... part of the api wouldn't be loaded

I'm still not happy with that circular import stuff I'm currently doing... there must be a better way to better split stuff built with flask? To investigate...