* Enhanced -online to also work for p4broker and p4p.
* Added comparison check for live running vs. symlink'd version of servers
(p4d, p4broker, and p4p). This is a part of the solution for SDP-625.
* When checking for symlinks, also added checks that symlink target dirs exist.
* For the special case where 'p4d' and 'p4p' are running on the same machine
(according to the Instance Bin init scripts), proxy misconfiguration issues
such as a missing /p4/N/cache symlink or a missing /hxdepots/p4/N/cache
directory are reported as Warnings rather than Errors.