Added identifier.pl and updated notice2server.pl

Changes in notice2server.pl:
- Add ChanServ to default list of nicks
- Fix notices not being displayed in the server tab if the network
supplies a network name different from the one set in network list
- Don't let other scripts see the original notice (results in duplicate
notices for scripts)
- Set priority to high so that scripts normal priority scripts can't be
executed before this one (also results in duplicate notices for them)

Changes in readme:
- Added other useful scripts and sources