Fixed bug where /p4/N/bin ownership is not set correctly (owned by root).
Fixed issue with missing symlink creation for replicas.
Made compliant with shellcheck.sh v0.6.0, driving many changes and
fixing potential glob-expansion issues.
Fixed an issue with '-test' not setting DB1/DB2.
Removed unused/obsolete MD def'n.
Added 'p4d_ha' server type to distinguish from existing 'p4d_standby'
type, and added comments to mkdirs.cfg to note that p4d_standby is
for pre-2018.1 servers, and p4d_ha is for 2018.1+. The distinction
is that P4D 2018.1 introduced rpl.journalcopy.location, which
changes P4D behaviors and corresponding best practice for placement
of the actively pulled journal file for 'journalcopy' replicas.
For pre-2018.1, we use /hxlogs/p4/N/journals.rep, and for 2018.1+
with rpl.journalcopy.location=1 set, we us /hxdepots/p4/N/checkpoints.<tag>.