Merge #13578: [depends, zmq, doc] upgrade zeromq to 4.2.5 and avoid deprecated zeromq api functions

f1bd03eb01 [depends, zmq, doc] upgrade zeromq to 4.2.5 and avoid deprecated zeromq api functions (mruddy)

Pull request description:

  Upgrade the ZeroMQ dependency from version 4.2.3 to the latest stable version 4.2.5.

  This PR Follows the lead of https://github.com/bitcoin/bitcoin/pull/11986.

  I upgraded both patch files to correspond to the version `4.2.5` libzmq files.
  I assume doing so is still necessary and correct.

  Without updating the patch line numbers, things appear to work, but you get extra log messages while building `depends` because things don't exactly match, e.g.:
  ```
  /bitcoin/depends> make zeromq
  Extracting zeromq...
  /bitcoin/depends/sources/zeromq-4.2.5.tar.gz: OK
  Preprocessing zeromq...
  patching file src/windows.hpp
  Hunk #1 succeeded at 58 (offset 3 lines).
  patching file src/thread.cpp
  Hunk #1 succeeded at 307 with fuzz 2 (offset 87 lines).
  Hunk #2 succeeded at 323 with fuzz 2 (offset 90 lines).
  ```
  Updating the patches seemed cleaner, so I did it. Note that libzmq had some whitespace changes, so that's why the updated patches do too.

  More info: https://github.com/zeromq/libzmq/releases/tag/v4.2.5

  tags: libzmq, zmq, 0mq

Tree-SHA512: 78659dd276b5311e40634b1bbebb802ddd6b69662ba3c84995ef1e3795c49a78b1635112c7fd72a405ea36e2cc3bdeb84e6d00d4e491a349bba1dafff50e2fa5

src/zmq/zmqnotificationinterface.cpp

@@ -81,10 +81,14 @@ CZMQNotificationInterface* CZMQNotificationInterface::Create()
 // Called at startup to conditionally set up ZMQ socket(s)
 bool CZMQNotificationInterface::Initialize()
 {
+    int major = 0, minor = 0, patch = 0;
+    zmq_version(&major, &minor, &patch);
+    LogPrint(BCLog::ZMQ, "zmq: version %d.%d.%d\n", major, minor, patch);
+
     LogPrint(BCLog::ZMQ, "zmq: Initialize notification interface\n");
     assert(!pcontext);
 
-    pcontext = zmq_init(1);
+    pcontext = zmq_ctx_new();
 
     if (!pcontext)
     {
@@ -127,7 +131,7 @@ void CZMQNotificationInterface::Shutdown()
             LogPrint(BCLog::ZMQ, "   Shutdown notifier %s at %s\n", notifier->GetType(), notifier->GetAddress());
             notifier->Shutdown();
         }
-        zmq_ctx_destroy(pcontext);
+        zmq_ctx_term(pcontext);
 
         pcontext = nullptr;
     }