adds email notification on suggestion creation
adds bcc to suggestions' notification email
adds email notification on proposal creation
Merge remote-tracking branch 'stream7/euruko2013' into 17-email_notifications. Refs #17.

Conflicts:
	app/controllers/suggestions_controller.rb
Title and comment for new proposal mails.
Include the proposal title on suggestion notification. Refs #17.
adds edit suggestion functionality for admins
absolute path for partial required when validation fails
Fix minor error
Sanitize user input
Use letter_opener for development in order to see the mails sent. Refs #17.
Code styling and cleanups.
Better title for new proposal notifications. Refs #17.
Proposals are anonymous even for the committee! Refs #17.
Minor fix in new suggestion notification mail. Refs #17.
Code styling.
Basic testing that proposals and suggestions controllers deliver emails after create. Refs #17.
Opt-out from new suggestion notifications for proposal authors. Refs #17.
A somewhat better layout for mails.
Until a user with no email can actually add it hide the option to handle notification settings. Refs #17.