Stylesheets cleanup

+ Added variables to stylesheets
* Modified  topbar
* Stylesheets cleanup
* Fixed a typo
Added user email field

+ Added user email field
* Fixed user/edit form
* Fixed user/register form
Gravatar integration

+ Added gravatar to user view
Udpated user session managment

* Stores id instead of user in session
Fixed user deletion while connected

* Fixed case where user is not found but connected
Fixes after merge

* use of get_user

Merge github.com:adaedra/pfa-idea3

Conflicts:
	db/schema.rb