Added a SERVERID variable to p4_vars and updated backup_functions to use it.
Changed the location and the names of the config files so that they could
live in /p4/common/config (You're welcome Tom). The files names are:
p4_$INSTANCE.vars will now set P4REPLICA to FALSE if SERVERID matches
MASTERNAME, otherwise it is TRUE.
This change means that a user must change server.id now in order to change
the role of the server rather than changing the instance vars file. This
makes more sense to a user that is reading the admin guide about server.id
rather than overwriting the file based on a setting that isn't in the admin guide.
Change mkdirs to reflect all of the above changes.