CRCs: Update comments and improve CSIT checks.

CRCs: Update comments and improve CSIT checks.

+ Restore alphabetic order in yaml.
+ Mark the lisp messages verified to be covered by dev instead of virl.
+ Mark the GBP messages verified by devicetest now.
+ Mark acl_add_replace as dev and create_subif as perf.
+ Mark ip_probe_neighbor as unused L1.
+ Improve loadbalancer comments.
  - Nat4 testcase is described, even if not merged yet.
+ Forget reported CRC after initial dir report,
  and report them again (once) in test cases (if hit).
  With this, single run (with fail on crc off) gives full info.
+ Small improvements to CRC library docstrings and messages.

Change-Id: Ic1cfad45e10d437be827af2a89eac49e25267b59
Signed-off-by: Vratko Polak <vrpolak@cisco.com>