Migration to RickShaw graph library.

Custom version of rickshaw to adapt with this project. Massive use of
ajax to avoid too large data series.
Code structure
Login bug fix
Flash message style improvement
Merge branch 'dev' of https://github.com/frco9/ecobox into dev

Conflicts:
	.gitignore
	Gemfile.lock
	app/controllers/users_controller.rb
	lib/tasks/sample_data.rake