Annotations changed
Renamed TexComments to Remarks

The idea is to create a new table to store unique Tex comments.
A Remark will reference a TexComment
New model - tex_comment - defined

TexComment will have the actual TeX plus some book-keeping data for
each TeX comment

An examiner would henceforth give Remarks = TexComment + position information + examiner_id
A Remark now belongs_to TexComment and a TexComment has_many Remarks
 minor cosmetic change
Not tracking usage count. But tracking 'triviality' of TexComment ...

Usage count is most reliably inferred
Transferred (unique) comments from Remarks to TexComments ...

Also, changed the underlying logic for storing and retrieving comments
First version of heuristic to ascertain whether or not a comment is trivial