mkrep.sh v3.1.0:
* Added infer_type_tag() function with logic to determine if P4TARGET is
filtered or not.
* Discouraged use of 'ro' and 'rom' types (as they don't support 'p4 failover').
* Clarified usage to indicate daisy chaining is acceptable from
forwarding replicas.
* Added preflight check to avoid accidental overwrite of existing server spec.
* Added '-os' option to overwrite existing server spec intentionally.
* Re-added test for mkrep.sh to default test suite after fixing the test.
* Added '-N' option to fully support server spec naming standard that allows
for things like 'p4d_edge2_syd' and 'p4d_edge3_syd'. Added docs for same.