Add design of walls on Home page

* created directive to render wall categories with people
* created initial design for walls
* added hardcoded data for "Wall of Fame" and "Wall of Shame"
Add walls controller

* implemented initial 3 wall of fame queries
* implemented initial 2 wall of shame queries
Add missing files

* added walls_controller, test and helper classes
Show live Walls data on Home page

* implemented service and controller for Walls resource
Clean up service.js

* removed commented out code