Move reload icon from diff editor to core

It is a generic icon, and will for example also be used
in the Help plugin. Also make it more round and add a 2x variant
for HiDPI.

Change-Id: I2ad4fc1e2d2766042646a47483f129447c2c3c25
Reviewed-by: Alessandro Portale <alessandro.portale@digia.com>

src/plugins/diffeditor/diffeditor.cpp

@@ -333,7 +333,7 @@ QWidget *DiffEditor::toolBar()
     slotDescriptionVisibilityChanged();
 
     QToolButton *reloadButton = new QToolButton(m_toolBar);
-    reloadButton->setIcon(QIcon(QLatin1String(Constants::ICON_RELOAD)));
+    reloadButton->setIcon(QIcon(QLatin1String(Core::Constants::ICON_RELOAD_GRAY)));
     reloadButton->setToolTip(tr("Reload Editor"));
     m_toolBar->addWidget(reloadButton);
 

src/plugins/diffeditor/diffeditor.qrc

@@ -1,6 +1,5 @@
 <RCC>
     <qresource prefix="/diffeditor">
-        <file>images/reload.png</file>
         <file>images/sidebysidediff.png</file>
         <file>images/unifieddiff.png</file>
         <file>images/topbar.png</file>

src/plugins/diffeditor/diffeditorconstants.h

@@ -42,7 +42,6 @@ const char G_TOOLS_DIFF[] = "QtCreator.Group.Tools.Options";
 
 const char ICON_SIDE_BY_SIDE_DIFF[]  = ":/diffeditor/images/sidebysidediff.png";
 const char ICON_UNIFIED_DIFF[]       = ":/diffeditor/images/unifieddiff.png";
-const char ICON_RELOAD[]             = ":/diffeditor/images/reload.png";
 const char ICON_TOP_BAR[]            = ":/diffeditor/images/topbar.png";
 
 } // namespace Constants