use #ifdef QT_UI to distinguish Qt UI instead of hardcoded #if 0

bitcoin-qt.pro

@@ -2,6 +2,7 @@ TEMPLATE = app
 TARGET =
 DEPENDPATH += .
 INCLUDEPATH += src src/json src/cryptopp src/qt
+DEFINES += QT_GUI
 
 # for boost 1.37, add -mt to the boost libraries
 unix:LIBS += -lssl -lcrypto -lboost_system -lboost_filesystem -lboost_program_options -lboost_thread -ldb_cxx
@@ -66,7 +67,7 @@ HEADERS += src/qt/bitcoingui.h \
     src/qt/guiconstants.h \
     src/qt/optionsmodel.h \
     src/qt/monitoreddatamapper.h \
-    src/externui.h \
+    src/qtui.h \
     src/qt/transactiondesc.h \
     src/qt/transactiondescdialog.h \
     src/qt/bitcoinamountfield.h

src/headers.h

@@ -100,7 +100,11 @@
 #include "uibase.h"
 #include "ui.h"
 #else
-#include "externui.h"
+#ifdef QT_GUI
+#include "qtui.h"
+#else
+#include "noui.h"
+#endif
 #endif
 
 #ifdef GUI

src/init.cpp

@@ -75,8 +75,7 @@ void HandleSIGTERM(int)
 //
 // Start
 //
-#if 0
-#ifndef GUI
+#if !defined(QT_GUI) && !defined(GUI)
 int main(int argc, char* argv[])
 {
     bool fRet = false;
@@ -88,7 +87,6 @@ int main(int argc, char* argv[])
     return 1;
 }
 #endif
-#endif
 
 bool AppInit(int argc, char* argv[])
 {
@@ -228,10 +226,8 @@ bool AppInit2(int argc, char* argv[])
         fServer = GetBoolArg("-server");
 
     /* force fServer when running without GUI */
-#if 0
-#ifndef GUI
+#if !defined(QT_GUI) && !defined(GUI)
     fServer = true;
-#endif
 #endif
     fPrintToConsole = GetBoolArg("-printtoconsole");
     fPrintToDebugger = GetBoolArg("-printtodebugger");
@@ -529,11 +525,9 @@ bool AppInit2(int argc, char* argv[])
         SetStartOnSystemStartup(true);
 #endif
 
-#if 0
-#ifndef GUI
+#if !defined(QT_GUI) && !defined(GUI)
     while (1)
         Sleep(5000);
-#endif
 #endif
 
     return true;