Add count of exclusively covered digests to each ignore rule

golden/frontend/res/imp/ignores-page-sk.html

 <!--
    The <ignores-page-sk> custom element declaration.
 
   A container element to manage the any digests that should be ignored.
 
   Attributes:
     None
 
   Methods:
     pageSelected: This function has to be called if the page is selected
     via a route. It's  equivalent to the ready function, when we don't
     want to trigger loading the content unless a user selects the page.
 
     pageDeselected: Has to be called when the page goes out of view.
 
   Events:
     None
 
   Mailboxes:
     None
 
 -->
 
 <link rel="import" href="bower_components/polymer/polymer.html">
 <link rel="import" href="bower_components/paper-dialog/paper-dialog.html">
 <link rel="import" href="bower_components/iron-flex-layout/iron-flex-layout-classes.html">
 <link rel="import" href="bower_components/paper-fab/paper-fab.html">
 <link rel="import" href="bower_components/paper-input/paper-input.html">
 <link rel="import" href="bower_components/paper-dialog-scrollable/paper-dialog-scrollable.html">
+<link rel="import" href="bower_components/paper-tooltip/paper-tooltip.html">
 
 <link rel=import href="../common/imp/query.html">
 
 <link rel="import" href="ignore-summary-sk.html">
 <link rel="import" href="shared-styles.html">
 
 <dom-module id="ignores-page-sk">
   <template>
     <style include="shared-styles"></style>
     <style include="iron-flex iron-flex-alignment">
@@ skipping 10 matching lines @@
       #expiresHeader,
       #queryHeader,
       #noteHeader,
       #countHeader {
         display: inline-block;
         font-weight: bold;
         margin-right: 0.5em;
       }
 
       #nameHeader {
-        width: 15em;
+        width: 18em;
       }
 
       #updatedByHeader {
-        width: 15em;
+        width: 18em;
       }
 
       #expiresHeader {
-        width: 10em;
+        width: 5em;
       }
 
-      #countHeader {
-        width: 6em;
+      #countHeader  {
+        width: 8em;
       }
 
       #queryHeader {
         width: 20em;
       }
 
       #noteHeader {
         width: 20em;
       }
 
@@ skipping 32 matching lines @@
       }
 
     </style>
     <div class="layout vertical ignoresPageWrapper">
       <div class="layout horizontal">
         <div id=nameHeader>Name</div>
         <div id=expiresHeader>Expires</div>
         <div id=updatedByHeader>Updated By</div>
         <div id=queryHeader>Filter</div>
         <div id=noteHeader>Note</div>
-        <div id=countHeader>Ignored</div>
+        <div id=countHeader>Ignored  <iron-icon class="headerIcon" icon="icons:info-outline"></iron-icon>
+          <paper-tooltip>Number of images that match this rule: <br>
+             Exclusively matched images / All matched images
+           </paper-tooltip>
+        </div>
       </div>
       <div id=summaries class="vertical layout">
         <template is="dom-repeat" items={{ignores}}>
           <ignore-summary-sk value="{{item}}"></ignore-summary-sk>
         </template>
       </div>
     </div>
 
     <paper-dialog id="confirmDelete">
       <h2>Confirm Delete</h2>
@@ skipping 147 matching lines @@
       },
 
       _openDialog: function(isEdit) {
         this._isEdit = isEdit;
         this._readyToAdd();
         this.$.addEditDialog.open();
       }
     });
   </script>
 </dom-module>