Introduce -maxuploadtarget

* -maxuploadtarget can be set in MiB
* if <limit> - ( time-left-in-24h-cycle / 600 * MAX_BLOCK_SIZE ) has reach, stop serve blocks older than one week and filtered blocks
* no action if limit has reached, no guarantee that the target will not be  surpassed
* add outbound limit informations to rpc getnettotals

src/init.cpp

@@ -369,6 +369,7 @@ std::string HelpMessage(HelpMessageMode mode)
     strUsage += HelpMessageOpt("-whitebind=<addr>", _("Bind to given address and whitelist peers connecting to it. Use [host]:port notation for IPv6"));
     strUsage += HelpMessageOpt("-whitelist=<netmask>", _("Whitelist peers connecting from the given netmask or IP address. Can be specified multiple times.") +
         " " + _("Whitelisted peers cannot be DoS banned and their transactions are always relayed, even if they are already in the mempool, useful e.g. for a gateway"));
+    strUsage += HelpMessageOpt("-maxuploadtarget=<n>", strprintf(_("Tries to keep outbound traffic under the given target (in MiB per 24h), 0 = no limit (default: %d)"), 0));
 
 #ifdef ENABLE_WALLET
     strUsage += HelpMessageGroup(_("Wallet options:"));
@@ -1174,6 +1175,9 @@ bool AppInit2(boost::thread_group& threadGroup, CScheduler& scheduler)
         RegisterValidationInterface(pzmqNotificationInterface);
     }
 #endif
+    if (mapArgs.count("-maxuploadtarget")) {
+        CNode::SetMaxOutboundTarget(GetArg("-maxuploadtarget", 0)*1024*1024);
+    }
 
     // ********************************************************* Step 7: load block chain