BUG: Clear box icon renamed to be considered

We investigated this issue in depth with Jc in Salt Lake City and it is still a mystery why the old icon is used despite I changed its contents. We agreed that the best would be to simply rename the icon.

Fixes #501

Libs/Widgets/Resources/ctkWidgets.qrc

@@ -8,7 +8,7 @@
         <file>Icons/expand-down.png</file>
         <file>Icons/expand-up.png</file>
         <file>Icons/search.svg</file>
-        <file>Icons/clear.svg</file>
+        <file>Icons/clear2.svg</file>
         <file>Icons/Languages/ad.png</file>
         <file>Icons/Languages/ae.png</file>
         <file>Icons/Languages/af.png</file>

Libs/Widgets/ctkSearchBox.cpp

@@ -60,7 +60,7 @@ public:
 ctkSearchBoxPrivate::ctkSearchBoxPrivate(ctkSearchBox &object)
   : q_ptr(&object)
 {
-  this->clearIcon = QIcon(":Icons/clear.svg");
+  this->clearIcon = QIcon(":Icons/clear2.svg");
   this->searchIcon = QIcon(":Icons/search.svg");
   this->showSearchIcon = false;
   this->alwaysShowClearIcon = false;