Implement server side of spellchecking

[Paul Everitt]

Related to https://bugs.launchpad.net/karl3/+bug/398940, get a server-side view that implements the TinyMCE "protocol" for spellchecking.

- Unit and functional tests as appropriate.

- Make sure we get the OSI copyright statement into the top of Python files.

- Take into account the impact on developer sandboxes. Don't require Apache/PHP, for example. Try not to require external C libraries. Chat with Shane if you'd like to get his experience with Python spellchecking, though likely

- Try to avoid a separate process. If one is needed, get the development sandbox to crank one up with Supervisor, and get with the production folks to edit the modwsgi conf to spring one into action.

- Make a recommendation on approaches for JS testing, with extra credit for something that can be even partially automated/hands-free.

- Regarding supporting non-English spellchecking, I'm ok with leaving it out of scope for now. I don't know what the impact would be on the TinyMCE configuration (how does it determine the language?), the protocol, the dictionaries used, etc.

[Paul Everitt (paul-agendaless)]

I'll slot this for next week (M24) as Derek needs Mike for wrapping this up.

[Nat Katin-Borland (nborland)]

Looks good!