Move mimetype definitions to plugin specs

- Avoids the hassle of QRC files and manually registering mime types
- Avoids performance regressions because of mime types that are
  registered after mime database has been used
- Makes it technically possible to detect that a disabled plugin could
  handle a mime type if it was enabled

Change-Id: I373008b1b56e9c6b4853055f20b3eeb112a6eff9
Reviewed-by: Christian Stenger <christian.stenger@qt.io>
Reviewed-by: hjk <hjk@qt.io>

src/plugins/qmakeprojectmanager/qmakeprojectmanagerplugin.cpp

@@ -58,7 +58,6 @@
 #include <texteditor/texteditoractionhandler.h>
 #include <texteditor/texteditorconstants.h>
 #include <utils/hostosinfo.h>
-#include <utils/mimetypes/mimedatabase.h>
 #include <utils/parameteraction.h>
 
 #ifdef WITH_TESTS
@@ -83,8 +82,6 @@ bool QmakeProjectManagerPlugin::initialize(const QStringList &arguments, QString
     const Context projectContext(QmakeProjectManager::Constants::PROJECT_ID);
     Context projecTreeContext(ProjectExplorer::Constants::C_PROJECT_TREE);
 
-    Utils::MimeDatabase::addMimeTypes(QLatin1String(":qmakeprojectmanager/QmakeProjectManager.mimetypes.xml"));
-
     //create and register objects
     m_qmakeProjectManager = new QmakeManager;
     addAutoReleasedObject(m_qmakeProjectManager);