Merge pull request #119 from adamarla/master

- Removed Create a Group from help menu as it is now self explanatory...
Merge pull request #120 from adamarla/master

Merge branch 'master' of heroku.com:drona
Template files that should be used in every developers setup

bash_aliases -> standard aliases for use by developers
database.yml.template ->
  1. copy as database.yml locally
  2. Do NOT commit database.yml to Git
  3. Setup local postgres using the same username and password as specified in database.yml.template
Video model enhanced ...

Now that we are going to be creating content, videos become important
and therefore we need more info on them.

The new fields added classify videos as lectures, tutorials or historical lessons
Two new models - Course and Concept - added ..

Course makes a comeback - albeit with a different meaning
Added some query functions and callbacks in Concept
Topics don't belong to Courses - only Verticals

Deleted code is from a time when we used to map topics to school boards.
No longer.
Defined polymorphic association b/w videos, concepts and questions

Both concepts and questions can have videos
Distinguish b/w our teachers (online=true) and all others
Added price to courses. All prices in USD
Distinguishing between external teachers and internal online instructors

Internal instructors do not need to see demos and tutorials nor do they
need to be able to create sektions. External teachers do.

On the other hand, external teachers are not allowed to create courses
- which internal instructors can
Added description to videos

Ideally, 2-4 lines of text
Stylistic change: :a => b written as a: b
Some more changes like those in the last commit
[checkWhether]: Checks for 'class', 'attr' and 'data-*' attributes

Previosuly, it didn't do data-* checks
Minor stylistic change
A different initial left-panel for online instructors

They need to see only the quizzes they have made and the courses
they manage. Worksheets are created and published as students
register - unlike regular teachers who consciously make worksheets
Renamed Concept as Milestone ...

A course :has_many :milestones and within each milestone, many
topics could be covered. The titles and description of the videos
within a milestone will make it abundandtly clear what the concept
being covered is
Milestones do not need user provided names ...

They are just markers for book-keeping purposes - nothing more
Upgrading from Rails 3.1.10 to 3.2.11

Anticipate need for polymorphic has_many :through association which
wasn't well supported in 3.1.10