Review 27208

C. Thomas Tyler v4.3.0:
* Greatly enhanced documentation and examples.
* Before doing second journal rotation:
  - Added wait for 'p4 storage -w' (for 'to or thru' P4D 2019.1).
  - Added wait for 'p4 upgrades|grep -v completed' (for P4D 2020.2+)
* Added check for whether p4broker and p4p were online at the start
of upgrade processing. Only start those services that were running at
the beginning of processing are now started after the binaries and
symlinks are updated.  For the broker, only the broker with the default
configuration is stopped and started; DFM brokers are ignored by this
script (thus making this script compaitble with using DFM brokers).
* Fixed bug where '-c' (Protections table comment conversion) would
have failed due to 'p4d' addition of 'Update:' field to the Protections
table. Also generally enhanced logic to convert Protections table
* Added support for operation on proxy-only and broker-only hosts.
Processing of upgrades for p4d occur only if /p4/N/bin/p4d_N_init
script exists on the machine.
* Refined lexigraphical P4D version comparsion checks. v5.12.0:
* Added support for proxy-only and broker-only hosts.  The
existence of a *_init script in the instance bin dir for any of the
Helix server binaries p4d/p4p/p4broker indicate they are configured,
determining what tests are executed or skipped.
* Added check_file_x() function to check for execute bit on files.

In, fixed is_server_up() to avoid displaying
Tip: Use n and p to cycle through the changes.