Merge #12381: Remove more boost threads

004f999 boost: drop boost threads for [alert|block|wallet]notify (Cory Fields)
0827267 boost: drop boost threads from torcontrol (Cory Fields)
ba91724 boost: remove useless threadGroup parameter from Discover (Cory Fields)
f26866b boost: drop boost threads for upnp (Cory Fields)

Pull request description:

  This doesn't completely get rid of boost::thread, but this batch should be easy to review, and leaves us with only threadGroup (scheduler + scriptcheck) remaining.

  Note to reviewers: The upnp diff changes a bunch of whitespace, it's much more clear with 'git diff -w'

Tree-SHA512: 5a356798d0785f93ed143d1f0afafe890bc82f0d470bc969473da2d2aa78bcb9b096f7ba11b92564d546fb447d4bd0d347e7842994ea0170aafd53fda7e0a66e

src/wallet/wallet.cpp

@@ -34,7 +34,6 @@
 #include <future>
 
 #include <boost/algorithm/string/replace.hpp>
-#include <boost/thread.hpp>
 
 std::vector<CWalletRef> vpwallets;
 /** Transaction fee set by the user */
@@ -976,7 +975,8 @@ bool CWallet::AddToWallet(const CWalletTx& wtxIn, bool fFlushOnClose)
     if (!strCmd.empty())
     {
         boost::replace_all(strCmd, "%s", wtxIn.GetHash().GetHex());
-        boost::thread t(runCommand, strCmd); // thread runs free
+        std::thread t(runCommand, strCmd);
+        t.detach(); // thread runs free
     }
 
     return true;