Few inv related fixes:

- add missing strings and make inv strings a bit more consistent (imo)
- remove "unknown" types that were used to prevent errors thrown at user with old wallet,
  just log such errors in debug mode for "net" category. Should also make behaviour of functions
  relaing on CInv::IsKnownType() more adequate
  (and it doesn't make sense to warn users by throwing errors at them in such situations anyway I guess)

src/protocol.cpp

@@ -22,19 +22,15 @@ static const char* ppszTypeName[] =
     "tx lock request",
     "tx lock vote",
     "spork",
-    "masternode winner",
-    "masternode scan",
-    "masternode vote",
-    "masternode proposal",
-    "masternode quorum",
-    "masternode announce",
-    "masternode ping",
-    "unknown",
-    "unknown",
-    "unknown",
-    "unknown",
-    "unknown",
-    "unknown"
+    "mn winner",
+    "mn scan error",
+    "mn budget vote",
+    "mn budget proposal",
+    "mn budget finalized",
+    "mn budget finalized vote",
+    "mn quorum",
+    "mn announce",
+    "mn ping"
 };
 
 CMessageHeader::CMessageHeader()
@@ -133,7 +129,7 @@ CInv::CInv(const std::string& strType, const uint256& hashIn)
         }
     }
     if (i == ARRAYLEN(ppszTypeName))
-        throw std::out_of_range(strprintf("CInv::CInv(string, uint256) : unknown type '%s'", strType));
+        LogPrint("net", "CInv::CInv(string, uint256) : unknown type '%s'", strType);
     hash = hashIn;
 }
 
@@ -150,7 +146,8 @@ bool CInv::IsKnownType() const
 const char* CInv::GetCommand() const
 {
     if (!IsKnownType())
-        throw std::out_of_range(strprintf("CInv::GetCommand() : type=%d unknown type", type));
+        LogPrint("net", "CInv::GetCommand() : type=%d unknown type", type);
+
     return ppszTypeName[type];
 }