Rewrite IO engine.
Set buffer to readonly when selection intersects with proven areas.
Change ctrl+right keybinding to less annoying ctrl+enter.
Add a note about highlighting.
Don't advance if Coq reports an error.
Add indentation and comment rules.
Remove stale Basics.v.
Add completions.
Fixed syntax error handling.
More completions.
Merge pull request #1 from whitequark/master

A number of fixes to the base system and additions to the interface