Fix join_table for user likes comment relation.

Addresses #120
Merge pull request #126 from DevYah/C1_mnzaki_user_model_likes_relation

Fix join_table for user likes comment relation.
Add provider and uid fields to User model, as required by Omniauth.

Issue #74 and #91 need this
Remove redundant attr_accessible from User model.
Merge pull request #127 from DevYah/C1_mnzaki_#74_omniauth_migrations

Add provider and uid fields to User model, as required by Omniauth.
Issue #80, List ideas for Idea Submitter/Committee in dashboard.
Merge branch 'master' into C4_Gezeery_#80_dashboard_view_ideas_performance