Pass chain and client variables where needed

This commit does not change behavior. All it does is pass new function
parameters.

It is easiest to review this change with:

    git log -p -n1 -U0 --word-diff-regex=.

src/bitcoind.cpp

@@ -11,6 +11,7 @@
 #include <clientversion.h>
 #include <compat.h>
 #include <fs.h>
+#include <interfaces/chain.h>
 #include <rpc/server.h>
 #include <init.h>
 #include <noui.h>
@@ -58,6 +59,9 @@ static void WaitForShutdown()
 //
 static bool AppInit(int argc, char* argv[])
 {
+    InitInterfaces interfaces;
+    interfaces.chain = interfaces::MakeChain();
+
     bool fRet = false;
 
     //
@@ -164,7 +168,7 @@ static bool AppInit(int argc, char* argv[])
             // If locking the data directory failed, exit immediately
             return false;
         }
-        fRet = AppInitMain();
+        fRet = AppInitMain(interfaces);
     }
     catch (const std::exception& e) {
         PrintExceptionContinue(&e, "AppInit()");
@@ -178,7 +182,7 @@ static bool AppInit(int argc, char* argv[])
     } else {
         WaitForShutdown();
     }
-    Shutdown();
+    Shutdown(interfaces);
 
     return fRet;
 }