RPC, cosmetic: push down ReadHTTPStatus() calls into ReadHTTP() callers

ReadHTTPStatus() is currently overloaded:  In client mode, it properly parses
and receives an HTTP status line.  In server mode, it incorrectly parses the
HTTP request line as an HTTP status line.

This server mode bug has never mattered, because the RPC server never
cared about the URI (path) provided in the HTTP request.  That will change in
the future, so go ahead and begin fixing the problem.

This patch is cosmetic, and should result in NO behavior changes.

Further renames:
ReadHTTPHeader -> ReadHTTPHeaders
ReadHTTP -> ReadHTTPMessage

src/bitcoinrpc.cpp

@@ -377,7 +377,7 @@ int ReadHTTPStatus(std::basic_istream<char>& stream, int &proto)
     return atoi(vWords[1].c_str());
 }
 
-int ReadHTTPHeader(std::basic_istream<char>& stream, map<string, string>& mapHeadersRet)
+int ReadHTTPHeaders(std::basic_istream<char>& stream, map<string, string>& mapHeadersRet)
 {
     int nLen = 0;
     loop
@@ -402,17 +402,15 @@ int ReadHTTPHeader(std::basic_istream<char>& stream, map<string, string>& mapHea
     return nLen;
 }
 
-int ReadHTTP(std::basic_istream<char>& stream, map<string, string>& mapHeadersRet, string& strMessageRet)
+int ReadHTTPMessage(std::basic_istream<char>& stream, map<string,
+                    string>& mapHeadersRet, string& strMessageRet,
+                    int nProto)
 {
     mapHeadersRet.clear();
     strMessageRet = "";
 
-    // Read status
-    int nProto = 0;
-    int nStatus = ReadHTTPStatus(stream, nProto);
-
     // Read header
-    int nLen = ReadHTTPHeader(stream, mapHeadersRet);
+    int nLen = ReadHTTPHeaders(stream, mapHeadersRet);
     if (nLen < 0 || nLen > (int)MAX_SIZE)
         return HTTP_INTERNAL_SERVER_ERROR;
 
@@ -434,7 +432,7 @@ int ReadHTTP(std::basic_istream<char>& stream, map<string, string>& mapHeadersRe
             mapHeadersRet["connection"] = "close";
     }
 
-    return nStatus;
+    return HTTP_OK;
 }
 
 bool HTTPAuthorized(map<string, string>& mapHeaders)
@@ -944,7 +942,12 @@ void ThreadRPCServer3(void* parg)
         map<string, string> mapHeaders;
         string strRequest;
 
-        ReadHTTP(conn->stream(), mapHeaders, strRequest);
+        // Read HTTP status (um, we mean, HTTP request line)
+        int nProto = 0;
+        ReadHTTPStatus(conn->stream(), nProto);
+
+        // Read HTTP message headers and body
+        ReadHTTPMessage(conn->stream(), mapHeaders, strRequest, nProto);
 
         // Check authorization
         if (mapHeaders.count("authorization") == 0)
@@ -1076,10 +1079,15 @@ Object CallRPC(const string& strMethod, const Array& params)
     string strPost = HTTPPost(strRequest, mapRequestHeaders);
     stream << strPost << std::flush;
 
-    // Receive reply
+    // Receive HTTP reply status
+    int nProto = 0;
+    int nStatus = ReadHTTPStatus(stream, nProto);
+
+    // Receive HTTP reply message headers and body
     map<string, string> mapHeaders;
     string strReply;
-    int nStatus = ReadHTTP(stream, mapHeaders, strReply);
+    ReadHTTPMessage(stream, mapHeaders, strReply, nProto);
+
     if (nStatus == HTTP_UNAUTHORIZED)
         throw runtime_error("incorrect rpcuser or rpcpassword (authorization failed)");
     else if (nStatus >= 400 && nStatus != HTTP_BAD_REQUEST && nStatus != HTTP_NOT_FOUND && nStatus != HTTP_INTERNAL_SERVER_ERROR)