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/nim/nimplugin.cpp

@@ -42,7 +42,6 @@
 
 #include <coreplugin/fileiconprovider.h>
 #include <projectexplorer/toolchainmanager.h>
-#include <utils/mimetypes/mimedatabase.h>
 
 #include <QtPlugin>
 
@@ -69,8 +68,6 @@ bool NimPlugin::initialize(const QStringList &arguments, QString *errorMessage)
 
     ProjectExplorer::ToolChainManager::registerLanguage(Constants::C_NIMLANGUAGE_ID, Constants::C_NIMLANGUAGE_NAME);
 
-    MimeDatabase::addMimeTypes(QLatin1String(":/Nim.mimetypes.xml"));
-
     addAutoReleasedObject(new NimSettings);
     addAutoReleasedObject(new NimSnippetProvider);
     addAutoReleasedObject(new NimEditorFactory);