Updated:
  BILL_TYPE to include more patterns.
Added subpatterns:
  CELL_AND_DOMAIN_AND_TYPE for request transfers.
  PNFSID_TSIZE_OR_ZERO and UNKNOWN_OR_SUNIT_OR_NOTHING for requests
  REQUESTDN for request and srm removes
Added patterns to match with grok:
  REQUEST_CLASSIC: for normal :request
  REQUEST_DCAP: for DCAP. dcap field is messy and could be improved.
  REMOVE_ON_POOL: for what looks like remove commands sent to pool, with RemoveFiles=
  REMOVE_CLASSIC: normal :removes
  REMOVE_SRM: for SRM removes