Themed Icons: Introduce Utils::Icon

Instead of describing icons via file name or in the themed icons case
via
a string that is a list of mask/color pairs, we have now a class for it.

Icons are now listed in per-plugin *icons.h headers.

RunControl::m_icon was The only place left where an icon property was in
fact a string. This patch changes that member to be a Utils::Icon.

Change-Id: Ibcfa8bb25e6d2e330c567ee7ccc0b97ead603177
Reviewed-by: Eike Ziller <eike.ziller@theqtcompany.com>

src/plugins/coreplugin/infobar.cpp

@@ -30,7 +30,7 @@
 
 #include "infobar.h"
 
-#include "coreconstants.h"
+#include "coreicons.h"
 #include "icore.h"
 
 #include <utils/theme/theme.h>
@@ -251,7 +251,7 @@ void InfoBarDisplay::update()
 
         if (info.cancelButtonText.isEmpty()) {
             infoWidgetCloseButton->setAutoRaise(true);
-            infoWidgetCloseButton->setIcon(QIcon(QLatin1String(Constants::ICON_CLEAR)));
+            infoWidgetCloseButton->setIcon(Icons::CLEAR.icon());
             infoWidgetCloseButton->setToolTip(tr("Close"));
             if (infoWidgetSuppressButton)
                 hbox->addWidget(infoWidgetSuppressButton);