adding (sign in/sign up) page for login

using 'twitter_bootstrap_form_for' for sign in/sign up
Merge branch 'master' of github.com:anilmaurya/tip4commit

Conflicts:
	Gemfile
	app/assets/stylesheets/application.css
	app/views/devise/confirmations/new.html.haml
	app/views/devise/passwords/edit.html.haml
	app/views/devise/passwords/new.html.haml
	app/views/devise/registrations/edit.html.haml
	app/views/devise/registrations/new.html.haml
	app/views/devise/sessions/new.html.haml