Fixed BasePageChooserPanel.render_js()

Addresses the "ForeignKey null=False" issue; new instances were throwing an exception, which prevented the edit handler from rendering the proper JavaScript in _editor_js.html.
Remove not needed messages.mo files from tree
Add new translations
Docs docs

How to author and build Wagtail docs
Merge pull request #137 from spapas/master

Add new translations & remove some stale message.mo files
Better docs docs

Link to online rst editor.
Roadmap page in docs
Specify Django 1.6 only in requirements (1.7 is going to require compatibility fixes)
repair collateral damage from a hail of bullet points
Merge branch 'master' of github.com:torchbox/wagtail
OS X installation instructions
Merge branch 'bpcp-fix' of https://github.com/rfosterslo/wagtail into rfosterslo-bpcp-fix
Add rfosterslo as contributor
Merge branch 'master' of github.com:torchbox/wagtail
prepare to release 0.2
Roadmap update and auto doc builder
auto doc builder notes