added per server and world pre- and suffixes and display options
applied changes to help
renamed for future migrators
Revert "renamed for future migrators"

This reverts commit 0821957625772b53236bb92517593d55b0703f77.
formatting
added new mysql backend, implements #26
fixed issues with new backend
fixed getuser query
fixed reading from resultset
fixed nullpointer
detect non-existing users
updated error message for new backend
fixed data saving
implemented recursive inheritances to groups; closes #20
get the value not the server