Adding new file will rebuild everything

When i add a new class, then all files will be run with moc and build again.

Simple pro file is enough to reproduce, see NewFileRebuild.7z

This will lead to long wait times with big projects.

1. open pro file with Qt VS tools
2. build
3. add new class "QtClass" (with popup menu "Add Qt class") and build:
   1> Moc'ing QtClass.h...
   1> QtClass.cpp
   1> moc_QtClass.cpp
4. change something in QtClass.cpp and build:
   1> QtClass.cpp
5. add new class "QtClass2" (with popup menu "Add Qt class") and build:
   1> Moc'ing QtClass.h...
   1> Moc'ing QtClass2.h...
   1> QtClass2.cpp
   1> moc_QtClass.cpp
   1> moc_QtClass2.cpp
6. change something in QtClass2.cpp and build:
   1> QtClass2.cpp
7. change something in main.cpp and build:
   1> main.cpp
8. add new class "QtClass3" (with popup menu "Add Qt class") and build:
   1> Moc'ing QtClass.h...
   1> Moc'ing QtClass2.h...
   1> Moc'ing QtClass3.h...
   1> QtClass3.cpp
   1> moc_QtClass.cpp
   1> moc_QtClass2.cpp
   1> moc_QtClass3.cpp
9.  add new class "TESTClass" (no Q_OBJECT makro) and build:
   1> Moc'ing QtClass.h...
   1> Moc'ing QtClass2.h...
   1> Moc'ing QtClass3.h...
   1> TESTClass.cpp
   1> moc_QtClass.cpp
   1> moc_QtClass2.cpp
   1> moc_QtClass3.cpp