Fixed bug with user search.

The bug was nullPointerException if user doesn't exist. Now a message is displayed instead of crashing and erroring.
Fixed bug with returning userDTO = null in search form, selecting PO and SM works.

There was a naaaaasty bug with SingleUserSearchDialog returning userDTO = null and causing a nullPointerException. Had to write a calback to retrieve the user DTO.
Also the form for PO and SM selection now works in ProjectRegistrationForm.
Adding project to database (prototype).
Save project to database. One tiny bug remains.

Project name validation works - two projects can't be the same. But the team gets stored again despite the project exists warning.
Save project to database woooooorks!!!
Merge branch 'project_register'