Qt4projectManager: Refactor Qt4Target, split up in per target classes

Almost(*) all of the symbian and maemo specific code is now theoretically
moveable to a separate plugin. Thus making it possible to implement
new targets in a plugin.

(*) Noteable missing is the qtversion, which needs to be split up
per target too.

Also fixes
Task-Nr: QTCREATORBUG-2440

Reviewed-By: hunger
Reviewed-By: ck

src/plugins/qt4projectmanager/qt-maemo/maemorunconfigurationwidget.cpp

@@ -42,6 +42,7 @@
 #include "maemoremotemountsmodel.h"
 #include "maemorunconfiguration.h"
 #include "maemosettingspages.h"
+#include "qt4maemotarget.h"
 
 #include <coreplugin/coreconstants.h>
 #include <coreplugin/icore.h>