Delete uncollated sets on source and witness delete
(Fix #89)
Check for collation set to have at least two collations

Fixes bug when trying to render side-by-side a comparison set with only
one witness within that set.

Helps with #84
Replace explicit state passing with _.bind()

Bring code into alignment with existing conventions used **everywhere else in
the project**
Add better _.bind() explanation
Embiggen checkbox font
Fix indentation
Make containers static, shrink right-hand side of UI.
Fix #78 Fix #88
merged