Design the frontend views

[mikejolley]

Stats box etc for insertion into the WIKI entries.

[danhauk]

• [x] Front-end editor
• [x] Revision history
• [x] Stats/last edit
• [x] Front-end diff viewer

[mikejolley]

• [x] Notices (submit edit with error or success)
• [x] Edit wiki in backend, the revisions widget
• [x] Contributions list (below content)