Starting the implementation of the new way to do the upload and crop for logos.
Refactoring of logos. Changed the call methods to accept the new upload version of logos.
Removing the old logos.
Removing old calls after removing old logos.
Fixed some errors launched after removing logos
Merge branch 'bug412' of https://github.com/mconf/mconf-web into branch-v2

Conflicts:
	Gemfile
	app/controllers/logos_controller.rb
	app/helpers/application_helper.rb
	app/helpers/events_helper.rb
	app/models/event.rb
	app/models/space.rb
	app/views/admissions/_invitation.html.erb
	app/views/admissions/index.html.erb
	app/views/spaces/_edit_space.html.erb
	app/views/spaces/_space_thumbnail.html.haml
	app/views/spaces/edit.html.haml
	config/routes.rb
	db/schema.rb