Renamed rubric.js.coffee to gp.js.coffee ( gp = grading panel )

The name rubric will be used for something else
Added schema changes and new models for new rubric scheme

Also, jquery-sortable shared amongst teachers and Admin.
We will need sortable as part of the rubric definition scheme
Temp commit. Is the initial, incomplete commit for programmable rubric
Merge branch 'master' into temp
Merge branch 'master' into temp
Rubric and Criterion should both have account_id and standard fields ...

Keep things similar in both models
Allow a criteria to be de-activated ...

A criterion - once added - should not be removed. If it is, then
there would be no way of deconstructing correctly which criterion were
chosen for a given feedback if the criterion has since been removed.

Instead, just deactivate the criterion in that rubric for future times.

Downside - We would limit a rubric to 32 criterion - including inactive ones
[New Rubric]: Step 1 -> added ability to create new rubrics and criteria ...

Next
----
  (step 2) bind criteria with rubrics
  (step 3) attach rubrics to exams / courses / both
[New rubric]: Step 2 -> Can now bind add/remove criteria from rubrics

TBD:
  (Step 3) -> Attaching rubrics to exams / courses
              - re-interpreting the field GradedResponse.feedback
  (Step 4) -> Loading the correct rubric during grading
Track whether or not a criterion is a red/orange flag issue
Added methods to mangle/unmangle feedback ...

... and calculate penalties given criterion_ids
Added method colour? to return colour code for a response given its mangled_fdb
Teachers & Exams track rubric + rubric can be active/inactive
Added a way to activate a rubric ...

Only one rubric can be active at any point in time. All other rubrics by
the same teacher / admin will be inactive

The active rubric is what will be attached to any exam made thereafter
Show per-rubric menu also for a newly added rubric
Merge branch 'master' into temp
Rubric_id removed from Teacher ...

The applicable rubric for any teacher can be calculated on the fly
Added query methods in Teacher & Exam to get applicable rubric id

For teachers, this means their currently active rubric OR the
currently active standard rubric

For exams, it means the rubric that was active for the teacher when the
exam was being built
Temporarily re-named before removal
[editable-rubrics]: Almost done ... Major changes committed

A little clean-up, code rationalization and a few bug-fixes still need
to be done. However, the essential wiring is in place with this commit.