set versions to 3.1 and added some pre-depends
moved ids to contrib
move keyring.gpg from scripts to extra
install ChangeLogs under /usr/share/doc
Merge branch 'jacalvo/3.1-packaging'

Conflicts:
	main/core/ChangeLog
	main/ebackup/ChangeLog
	main/printers/ChangeLog
	main/remoteservices/ChangeLog
	main/samba/ChangeLog
	main/squid/ChangeLog
	main/users/ChangeLog
	main/zarafa/ChangeLog