Refactor qbs project files.

- Use sub-projects.
- Move the main application and the application header products
  into dedicated files.
As a result, qtcreator.qbs becomes much simpler to understand,
consisting now of just a bunch of global properties and a few sub-project
references.

Change-Id: Ic7300d489d3982394be5ad1d12a79a2914320298
Reviewed-by: Joerg Bornemann <joerg.bornemann@digia.com>

src/plugins/plugins.qbs

@@ -0,0 +1,61 @@
+import qbs
+
+Project {
+    name: "Plugins"
+    references: [
+        "analyzerbase/analyzerbase.qbs",
+        "android/android.qbs",
+        "autotoolsprojectmanager/autotoolsprojectmanager.qbs",
+        "bazaar/bazaar.qbs",
+        "bineditor/bineditor.qbs",
+        "bookmarks/bookmarks.qbs",
+        "classview/classview.qbs",
+        "clearcase/clearcase.qbs",
+        "cmakeprojectmanager/cmakeprojectmanager.qbs",
+        "coreplugin/coreplugin.qbs",
+        "coreplugin/images/logo/logo.qbs",
+        "cpaster/cpaster.qbs",
+        "cpaster/frontend/frontend.qbs",
+        "cppeditor/cppeditor.qbs",
+        "cpptools/cpptools.qbs",
+        "cvs/cvs.qbs",
+        "debugger/debugger.qbs",
+        "debugger/ptracepreload.qbs",
+        "designer/designer.qbs",
+        "diffeditor/diffeditor.qbs",
+        "fakevim/fakevim.qbs",
+        "find/find.qbs",
+        "genericprojectmanager/genericprojectmanager.qbs",
+        "git/git.qbs",
+        "glsleditor/glsleditor.qbs",
+        "helloworld/helloworld.qbs",
+        "help/help.qbs",
+        "imageviewer/imageviewer.qbs",
+        "locator/locator.qbs",
+        "macros/macros.qbs",
+        "madde/madde.qbs",
+        "mercurial/mercurial.qbs",
+        "perforce/perforce.qbs",
+        "projectexplorer/projectexplorer.qbs",
+        "qbsprojectmanager/qbsprojectmanager.qbs",
+        "pythoneditor/pythoneditor.qbs",
+//        "qmldesigner/qmldesigner.qbs",
+        "qmljseditor/qmljseditor.qbs",
+        "qmljstools/qmljstools.qbs",
+        "qmlprofiler/qmlprofiler.qbs",
+        "qmlprojectmanager/qmlprojectmanager.qbs",
+        "qnx/qnx.qbs",
+        "qt4projectmanager/qt4projectmanager.qbs",
+        "qtsupport/qtsupport.qbs",
+        "remotelinux/remotelinux.qbs",
+        "resourceeditor/resourceeditor.qbs",
+        "subversion/subversion.qbs",
+        "tasklist/tasklist.qbs",
+        "texteditor/texteditor.qbs",
+        "todo/todo.qbs",
+        "updateinfo/updateinfo.qbs",
+        "valgrind/valgrind.qbs",
+        "vcsbase/vcsbase.qbs",
+        "welcome/welcome.qbs"
+    ]
+}