Too many db queries in note view

[ptgolden]

For two reasons:

1. Need select_related on note sections
   1a) select_related doesn't follow FK relationships where the fields can be null

2. We're querying the user for each reversion record individually in the template. That's dumb.

[ptgolden]

re: 1a -- Documents in note sections can be null because we said that maybe note sections can just be text content. Maybe it's worth making different models for different types of note sections, especially if we want to add something like, oh I don't know, timelines as a distinct section.