Implement automatic shutdown of deprecated Zcash versions

Closes #2274.

src/main.cpp

@@ -14,6 +14,7 @@
 #include "checkpoints.h"
 #include "checkqueue.h"
 #include "consensus/validation.h"
+#include "deprecation.h"
 #include "init.h"
 #include "merkleblock.h"
 #include "metrics.h"
@@ -2520,6 +2521,8 @@ bool static ConnectTip(CValidationState &state, CBlockIndex *pindexNew, CBlock *
     // Update cached incremental witnesses
     GetMainSignals().ChainTip(pindexNew, pblock, oldTree, true);
 
+    EnforceNodeDeprecation(pindexNew->nHeight);
+
     int64_t nTime6 = GetTimeMicros(); nTimePostConnect += nTime6 - nTime5; nTimeTotal += nTime6 - nTime1;
     LogPrint("bench", "  - Connect postprocess: %.2fms [%.2fs]\n", (nTime6 - nTime5) * 0.001, nTimePostConnect * 0.000001);
     LogPrint("bench", "- Connect block: %.2fms [%.2fs]\n", (nTime6 - nTime1) * 0.001, nTimeTotal * 0.000001);
@@ -3613,6 +3616,8 @@ bool static LoadBlockIndexDB()
         DateTimeStrFormat("%Y-%m-%d %H:%M:%S", chainActive.Tip()->GetBlockTime()),
         Checkpoints::GuessVerificationProgress(chainparams.Checkpoints(), chainActive.Tip()));
 
+    EnforceNodeDeprecation(chainActive.Height(), true);
+
     return true;
 }