Renamed column 'section' in 'sektions' to 'name'

This naming scheme is more in line with what we do elsewhere in other models
First steps towards enabling section creation by teachers ..

A new join-table - student roster - created to track which all
sections a students belongs to. Previously, a student could belong
to only one section
Migrations for transferring data from student -> studentRoster

Data transfer should always be done carefully and in steps. In this case:
  1. Create the student roster table
  2. Transfer sektion information from student to student roster
  3. Only then, remove sektion_id from student model
What grade/klass a student belongs to is now a direct property of the student

.. and not derieved from the sektion he/she belongs to - of which there can
now be more than one

A student should be able to belong to any sektion in his/her school
corresponding to his/her grade level
[Admin]: Ask for the grade level - not sektions - of newly added students
Added 2 new query methods - in_school and in-klass
 2 new query methods added
Specialization is now defined as (subject, klass) combo ..

Previously, it was defined as just the subject a teacher taught.
This new definition of specialization will be used to match the
teacher with sektions
[intermediate]: Don't reset to this ...

Commits made so that branch could be changed
 minor styling change
First commit towards implementing an expanded definition of specialization ...

We will henceforth use a teacher's specialization to match her with sections
of students. This is needed because eventually teachers would be able to create
their own sections/groupings
[step 2]: Admin should not create/edit sections ..

That should be left to the teacher to do as she wishes. Admin
should need only edit the student and faculty list. All other mappings/groupings
are context-specific - which the Admin can't know
First steps towards getting rid of faculty rosters ..

Here is what we are drifting towards:

What klass a student belongs to is a fundamental property of the student. Similarly,
what klass a sektion/grouping is for is its fundamental property. A student
can therefore belong to any sektion that is for the klass the student is in

Control over defining/editing sektions is now with the teacher. She can create
'public' sektions - visible to every other teacher in school - or private ones
- visible only to her

Faculty rosters is therefore a redundant concept. A teacher needs to see only
sektions of students - grouped by the klass/grade level - even if they haven't
been defined by her
New method - overlayJson - added ..

Unlike loadJson, this method does *not* create any swiss-knives or
edits the HTML in any way. It only tries to check/uncheck checkboxes
and/or radio buttons within any existing hierarchy
Added marker attribute to .list-item ..

Marker needed for scroll.overlayJson to work properly
Teacher specializations - not roster - now loaded

Rosters is a concept we are trying to move away from now
displayJson takes an optional argument for ticker ..

Simply specify the JSON key whose values is to be put into swiss-knife
micro-ticker as the last argument
Order sektions by klass
Logic for getting sektions (for a teacher) and students (in a sektion) modified ..

.. now that we are by-passing faculty roster and given that a student can belong
to multiple sektions
Merge branch 'master' into dev