clean Gemfile
frontend now resides in https://github.com/hendrikb/spatio-frontend
move backend_service to service.rb
move proof of concepts to demo dir
move demo example data to demo dir
update README
add activerecord and rgeo gems
add gitigore
Merge branch 'master' of github.com:hendrikb/spatio-backend

Conflicts:
	Gemfile
	Gemfile.lock
Merge branch 'master' of github.com:hendrikb/spatio-backend into convert_data

Conflicts:
	.gitignore
	Gemfile