SQL schema for persistence-pg
Infrastructure: Cabal files, License, PB generator script
Basic configuration parser finished.

Added SAVESETTINGS/GETSETTINGS types to the persistence protocol for
future use.
Added some query functions to the Database module
Database query functions completed.
Timestamp length had been too short (only 20 chars aren't enough)
PersistencePg is still in debugging phase, but alpha-ready
Merge branch 'persistence-pg'

Conflicts:
	protocols/webapp.proto
Important fixes for brokerm webapp, persistence-pg

- Fixed severe problems in broker when handling SAVESETTINGS/GETSETTINGS
requests
- Webapp didn't return the message body when requesting saved messages.
- persistence-pg needed some code cleanup
Fixed wrong constructor calls in broker; multi-threaded persistence-pg