Display time span on task elment for drag and resize.

* Display time range on assigned tasks during resize and drag.

* Use "ng-bind" directive instead of double-curly markup for displaying time
  range on task element because element is copied for dragging and the markup
  is not preserved to the copy.

* Add functions that give values to the closest 5 or 15;
Use bootstrap css/js for task modals.  Add display of task duration.

* Add "min2Str" utility function to convert an integer representing minutes into
  a formatted string showing hours and minutes.
* Place a watch on task element's scope on it's task's "duration" and "start" to
  apply those to the likewise named properties of that scope.
* Add a displayed duration to task element.
* Use Bootstrap modal js and styles for task create/edit modal.  Update task
  modal inputs.  TODO: update logic in taskModal directive to work with new
  inputs.
Fix devise parameter bug with sign up.

* Modify devise registrations parameter sanitization to allow "name" field to be
  submitted.
Switch to postgres.
Configure mail settings and pull certain config from env.

* Configure Action Mailer smtp for development and production.
* Configure mail settings for devise.
* Raise mail delivery errors on development.
* Get secret keys and other application config from environment variables:
  MAIL_HOST, MAIL_USER, MAIL_PASSWORD, DEVISE_SECRET_KEY, SECRET_KEY_BASE
Task form styling/validation. Fix bugs with task model de/serialization.

* Create new "Minutes" type for time durations.  Remove "min2Str" utility
  function.

* Remove "duration" property from task element's scope, and just use task
  model's duration.

* Add task create/edit styling and validation.

* Make "pixelFactor" a global variable in util.js, along with a global function
  to modify it.

* Move "beforeRespone" handler logic for "railsResourceFactory" instance into
  methods that receive task objects from the server.  The "beforeRespone"
  handler gets called whenever requests are made to the server and
  deserialization logic will be executed on existing client-side task objects
  that are already deserialized.

* Add a "Time" type string formatting method to be used with task create/edit
  forms, as well as logic to instantiate a using form time input.