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
Added some sanity checks in method shadows?
Loading previously used comments for question to be graded ...

Loading old comments makes the grading faster and more consistent.
The examiner does not have to type the same comment anew. And as
a result, any post-grading detection of plagiarism that relies on
comments will be more reliable
Trying to create a cleaner, leaner TeX in karo.jaxify()
Allow comments from all examiners for given question in typeahead
Added new method - germane_comments - to load comments given a QSelection

The code for this was previously in AccountsController. But its been moved
to the model
Load non-trivial comments every 5 minutes
Increased length of page_breaks_after and switch_versions_after column to 100 characters
Upping the timeout to 5.hours

Could this be the reason behind execution expired error?
Defined a new strict check - compiled?
[Big one]: WriteTex was incorrectly setting job_id to 0 before CompileTex could complete

As a result, a quiz would get enabled before its preview was fully ready
or its sample made
Removed all limit on 'signature' fields in Quiz and Worksheet
Time estimates for delayed_jobs made more accurate

Calculation for time estimates takes into account the type of operation.
In particular, calculations now assume that 3 jpegs per min. can be
generated during quiz preview

Now that the times are more accurate, the user can decide whether or not
to wait or logout