Branch: master

      1) Completed Mquest sending implementation from logged-in user's Mquests
         page.
      2) Added relations between User and Mquest.

============= Added (3)

       /db/migrate/20130104210350_remove_mentor_id_and_mentee_id_from_mquests.rb
       /db/migrate/20130104210535_add_from_user_and_to_user_to_mquests.rb
       /db/migrate/20130104210832_add_not_null_constraint_to_mquest_fields.rb

============= Updated (9)

      /db/schema.rb
        - Altered table MQUESTS.
          Removed columns: mentor_id and mentee_id
          Added columns: from_user and to_user

      /app/controllers/mquests_controller.rb
        - Updated implementation in method: create.
            a) Removed usage of :mentor_id and :mentee_id
            b) Creating a Mquest based on received params.

      /config/locales/en.yml
        - Added following:
            messages:
              success: "Successfully sent Mquest to %{user_name} for becoming his/her %{role}"
              failure: "Mquest sending failed to %{user_name} for becoming his/her %{role}"

            already_mquested: "Mquested"
            remquest: "Re-Mquest"
          under user.mquests

        - Added following:
              could_not_save_mquest: "Due to some technical problem could not send mquest.Please inform administrator about this."
          under user.mquests.errors

      /config/routes.rb
        - Removed following:
            match "/users/:mentor_id/mquest/:mentee_id/:role" => "mquests#create", via: :post, as: :mquest_as_mentor
            match "/users/:mentee_id/mquest/:mentor_id/:role" => "mquests#create", via: :post, as: :mquest_as_mentee

        - Added following:
            match "/users/:from/mquest/:to/:role" => "mquests#create", via: :post, as: :mquest

      /app/views/mquests/index.html.haml
        - Used updated routes for mquest.
        - If user has already sent a Mquest to a user as a mentor/mentee displaying
          about it against his name and also providing option to resent a Mquest.

      /app/models/user.rb
        - Added relationships with Mquest:
              has_many :mquests_received, class_name: 'Mquest', foreign_key: 'to_user', dependent: :destroy, source: :receiver
              has_many :mquests_sent, class_name: 'Mquest', foreign_key: 'from_user', dependent: :destroy, source: :sender

        - Removed unnecessary :source option from following relationships:
            has_many :mentors, through: :mentor_connections, source: :mentor
            has_many :mentees, through: :mentee_connections, source: :mentee

        - Added methods:
            a) mquest_sent?(as_role, to_user)
            b) mquest_received?(as_role, from_user)

      /app/models/mquest.rb
        - Removed :mentee_id, :mentor_id from attr_accessible list
        - Added :from_user, :to_user to attr_accessible list
        - Updated code in the class w.r.t changes mentioned above, wherever applicable

        - Added relationship with User:
            belongs_to :receiver, class_name: "User"
            belongs_to :sender, class_name: "User"

        - Fixed few bugs in method: remove_stale_mquests
        - Fixed a bug in method: set_token.
          Replaced
            ActiveSupport::SecureRandom.hex
          WITH
            SecureRandom.hex 16

          ActiveSupport::SecureRandom is deprecated in Rails 3.1 and removed in Rails 3.2.
          http://ruby-doc.org/stdlib-1.9.3/libdoc/securerandom/rdoc/SecureRandom.html
          should be used instead.
          Reference: https://github.com/scambra/devise_invitable/issues/159

        - Removed after_create callback:
            after_create :send_notification

      /app/mailers/user_mailer.rb
        - Updated code in method: mquest_email(mquest) w.r.t changes made
          in /app/models/mquest.rb

      /app/views/user_mailer/mquest_email.html.haml
        - Fixed the illegal nesting error thrown by Haml when the file was
          rendered.
        - Replaced
              @requestor and @requested
          WITH
              @from and @to