Custom asset chain client names (#1338)

* Allow setting client name via cli

* Add util.h for GetArg

src/clientversion.cpp

@@ -20,6 +20,7 @@
 #include "clientversion.h"
 
 #include "tinyformat.h"
+#include "util.h"
 
 #include <string>
 
@@ -34,7 +35,7 @@
  * for both bitcoind and bitcoin-core, to make it harder for attackers to
  * target servers or GUI users specifically.
  */
-const std::string CLIENT_NAME("MagicBean");
+const std::string CLIENT_NAME = GetArg("-ac_clientname", "MagicBean");
 
 /**
  * Client version number

src/init.cpp

@@ -571,6 +571,7 @@ std::string HelpMessage(HelpMessageMode mode)
     strUsage += HelpMessageOpt("-ac_cclib", _("Cryptoconditions dynamicly loadable library"));
     strUsage += HelpMessageOpt("-ac_ccenable", _("Cryptoconditions to enable"));
     strUsage += HelpMessageOpt("-ac_ccactivate", _("Block height to enable Cryptoconditions"));
+    strUsage += HelpMessageOpt("-ac_clientname", _("Full node client name, default 'MagicBean'"));
     strUsage += HelpMessageOpt("-ac_decay", _("Percentage of block reward decrease at each halving"));
     strUsage += HelpMessageOpt("-ac_end", _("Block height at which block rewards will end"));
     strUsage += HelpMessageOpt("-ac_eras", _("Block reward eras"));