- Fixed the inconsitency bug lately introduced. Adding networks is now

reenabled. Renaming and Deleting is still deactivated since they
aren't handled in a pretty manner.
- This fix enabled us to totally drop network names as
identifiers. BufferInfo::bufferName() is history.
- the buffergroup table is gone. SQLite Schemaversion is now 2.
- introduced: bool SignedId::isValid(). Please use this for future
validity checks.

WARNING: DISTCLEAN IS MANDATORY!