updated database schema because of new database structure
implemented all insert funtions
todo: data validation
updated functions because of new database schema
added classes to handle group and model request
updated forms and requests because of new database structure
updated 'Rollladen' request handler
adding a new user now generates automatically an empty standard group
and an empty standard room
fixed reading checkbox newsletter
started commenting handler functions
updated handler for adding a rollladen
fixed getRolladen problem
fixed return value
Merge branch 'dev'