Implement enhanced Ticket support:

Tickets are a mechanism to allow for the "out-of-order" execution of
transactions on the XRP Ledger.

This commit, if merged, reworks the existing support for tickets and
introduces support for 'ticket batching', completing the feature set
needed for tickets.

The code is gated under the newly-introduced `TicketBatch` amendment
and the `Tickets` amendment, which is not presently active on the
network, is being removed.

The specification for this change can be found at:
https://github.com/xrp-community/standards-drafts/issues/16

src/ripple/protocol/impl/TER.cpp

@@ -100,6 +100,7 @@ transResults()
         MAKE_ERROR(tefBAD_AUTH_MASTER,        "Auth for unclaimed account needs correct master key."),
         MAKE_ERROR(tefINVARIANT_FAILED,       "Fee claim violated invariants for the transaction."),
         MAKE_ERROR(tefTOO_BIG,                "Transaction affects too many items."),
+        MAKE_ERROR(tefNO_TICKET,              "Ticket is not in ledger."),
 
         MAKE_ERROR(telLOCAL_ERROR,            "Local failure."),
         MAKE_ERROR(telBAD_DOMAIN,             "Domain too long."),
@@ -150,6 +151,7 @@ transResults()
         MAKE_ERROR(temBAD_TICK_SIZE,          "Malformed: Tick size out of range."),
         MAKE_ERROR(temINVALID_ACCOUNT_ID,     "Malformed: A field contains an invalid account ID."),
         MAKE_ERROR(temCANNOT_PREAUTH_SELF,    "Malformed: An account may not preauthorize itself."),
+        MAKE_ERROR(temINVALID_COUNT,          "Malformed: Count field outside valid range."),
 
         MAKE_ERROR(terRETRY,                  "Retry transaction."),
         MAKE_ERROR(terFUNDS_SPENT,            "DEPRECATED."),
@@ -162,6 +164,7 @@ transResults()
         MAKE_ERROR(terPRE_SEQ,                "Missing/inapplicable prior transaction."),
         MAKE_ERROR(terOWNERS,                 "Non-zero owner count."),
         MAKE_ERROR(terQUEUED,                 "Held until escalated fee drops."),
+        {terPRE_TICKET, {"terPRE_TICKET", "Ticket is not yet in ledger."}},
 
         MAKE_ERROR(tesSUCCESS,                "The transaction was applied. Only final in a validated ledger."),
     };