Allow using UML profiles in textual and graphical editor

[seiferma]

UML profiles are an extension mechanism defined in the UML standard. They allow extending the UML meta model and tailoring it to the needs of specific domains. Allow to use profiles in the textual and graphical editor.

[seiferma]

• Support local profiles (client) on CDO server
• Setting of references in profiles
• Multi-valued features

The work shall stay in a separate branch and will be merged after 0.7.0