Added '-fast' flag to p4verify.ps1 quickly; uses '--only MISSING'.
Added '-nt' flag to p4verify.ps1 to not add '-t' on a replica.
If this change is approved/commited, next steps are:
* Generate C:\p4\1\bin\p4verify-fast.bat
* Generate C:\p4\common\bin\p4verify-fast.bat
* Updated docs re: Scheduled Tasks to discuss options, e.g.
Run the fast verify daily, and full verify weekly or monthly.
I do not suggest adding separate *.bat wrappers for the '-nt' option,
as that is an advanted option, probably not worth the clutter of
extra files (and we'd need combinations with/without -fast). That
'-nt' option can remain only an option to the PowerShell script.