Move help message out of AppInit2

- Solves #1278, attempts to address #1049
- Removes \t's from help message that are removed afterwards anyway
- Moves UI-specific command-line options help to UI code
- Moves "-detachdb" out of #ifdef USE_UPNP

src/init.h

@@ -11,6 +11,7 @@ extern CWallet* pwalletMain;
 
 void Shutdown(void* parg);
 bool AppInit(int argc, char* argv[]);
-bool AppInit2(int argc, char* argv[]);
+bool AppInit2();
+std::string HelpMessage();
 
 #endif