Add count of exclusively covered digests to each ignore rule

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

Index: golden/frontend/res/imp/ignores-page-sk.html
diff --git a/golden/frontend/res/imp/ignores-page-sk.html b/golden/frontend/res/imp/ignores-page-sk.html
index b57c76e39fd324818236c8806435928dc5c697ce..e5ffbb53a0ebc74bd7014935e04e7edcf0a48cc7 100644
--- a/golden/frontend/res/imp/ignores-page-sk.html
+++ b/golden/frontend/res/imp/ignores-page-sk.html
@@ -50,7 +50,8 @@
       #expiresHeader,
       #queryHeader,
       #noteHeader,
-      #countHeader {
+      #countHeader,
+      #exCountHeader {
         display: inline-block;
         font-weight: bold;
         margin-right: 0.5em;
@@ -68,7 +69,8 @@
         width: 10em;
       }
 
-      #countHeader {
+      #countHeader,
+      #exCountHeader  {
         width: 6em;
       }
 
@@ -123,6 +125,7 @@
         <div id=queryHeader>Filter</div>
         <div id=noteHeader>Note</div>
         <div id=countHeader>Ignored</div>
+        <div id=exCountHeader>Exclusive</div>

[mtklein, 2016/08/05 21:37:57]

Exclusively ignored?
Ignored by only this rule?

[stephana, 2016/08/08 15:13:53]

I don't think there is a good wording for the header alone. 
So I collapsed the two values into one column and added a tooltip to the header.

See

https://screenshot.googleplex.com/T3RsDzSjz10.png

       </div>
       <div id=summaries class="vertical layout">
         <template is="dom-repeat" items={{ignores}}>