Favicons in the vomnibar; remove support.

There are security issues with favicons as implemented previously.  This
commit removes favicon support entirely.

background_scripts/completion.coffee

@@ -26,7 +26,6 @@ class Suggestion
 
   generateHtml: ->
     return @html if @html
-    favIconUrl = @tabFavIconUrl or "#{@getUrlRoot(@url)}/favicon.ico"
     relevancyHtml = if @showRelevancy then "<span class='relevancy'>#{@computeRelevancy()}</span>" else ""
     # NOTE(philc): We're using these vimium-specific class names so we don't collide with the page's CSS.
     @html =
@@ -35,8 +34,7 @@ class Suggestion
          <span class="vimiumReset vomnibarSource">#{@type}</span>
          <span class="vimiumReset vomnibarTitle">#{@highlightTerms(Utils.escapeHtml(@title))}</span>
        </div>
-       <div class="vimiumReset vomnibarBottomHalf vomnibarIcon"
-            style="background-image: url(#{favIconUrl});">
+       <div class="vimiumReset vomnibarBottomHalf">
         <span class="vimiumReset vomnibarUrl">#{@shortenUrl(@highlightTerms(Utils.escapeHtml(@url)))}</span>
         #{relevancyHtml}
       </div>
@@ -294,7 +292,6 @@ class TabCompleter
       suggestions = results.map (tab) =>
         suggestion = new Suggestion(queryTerms, "tab", tab.url, tab.title, @computeRelevancy)
         suggestion.tabId = tab.id
-        suggestion.tabFavIconUrl = tab.favIconUrl
         suggestion
       onComplete(suggestions)
 

content_scripts/vimium.css

@@ -352,13 +352,6 @@ body.vimiumFindMode ::selection {
   padding: 2px 0;
 }
 
-#vomnibar li .vomnibarIcon {
-  background-position-y: center;
-  background-size: 16px;
-  background-repeat: no-repeat;
-  padding-left: 20px;
-}
-
 #vomnibar li .vomnibarSource {
   color: #777;
   margin-right: 4px;