Core: Remove unneeded qualifications

Mostly done using the following ruby script:
Dir.glob('**/*.cpp').each { |file|
  next if file =~ %r{src/shared/qbs|/qmljs/}
  s = File.read(file)
  s.scan(/^using namespace (.*);$/) {
    ns = $1
    t = s.gsub(/^(.*)\b#{ns}::((?!Const)[A-Z])/) { |m|
      before = $1
      char = $2
      if before =~ /"|\/\/|\\|using|SIGNAL|SLOT|Q_/
        m
      else
        before + char
      end
    }
    if t != s
      puts file
      File.open(file, 'w').write(t)
    end
  }
}

Change-Id: I5c6690f51488bf8ca3610ba9fb11e6e5fd814aaa
Reviewed-by: Christian Kandeler <christian.kandeler@theqtcompany.com>
Reviewed-by: hjk <hjk@theqtcompany.com>

src/plugins/coreplugin/coreplugin.cpp

@@ -66,7 +66,7 @@ CorePlugin::CorePlugin()
   , m_findPlugin(0)
   , m_locator(0)
 {
-    qRegisterMetaType<Core::Id>();
+    qRegisterMetaType<Id>();
 }
 
 CorePlugin::~CorePlugin()
@@ -181,12 +181,12 @@ bool CorePlugin::initialize(const QStringList &arguments, QString *errorMessage)
     }
 
     // Make sure we respect the process's umask when creating new files
-    Utils::SaveFile::initializeUmask();
+    SaveFile::initializeUmask();
 
     m_findPlugin->initialize(arguments, errorMessage);
     m_locator->initialize(this, arguments, errorMessage);
 
-    Utils::MacroExpander *expander = Utils::globalMacroExpander();
+    MacroExpander *expander = Utils::globalMacroExpander();
     expander->registerVariable("CurrentDate:ISO", tr("The current date (ISO)."),
                                []() { return QDate::currentDate().toString(Qt::ISODate); });
     expander->registerVariable("CurrentTime:ISO", tr("The current time (ISO)."),