templates: use CSS classes for diff styling

Use of inline style for diff styling led to significant browser memory
usage on large diffs. Moving the styling into CSS classes corrects this.

This patch is based on work from
https://bugzilla.mozilla.org/show_bug.cgi?id=766952
and
https://hg.mozilla.org/hgcustom/version-control-tools/rev/2c355a580af6

mercurial/templates/gitweb/map

@@ -105,9 +105,9 b" annotateline = '"
     <td><pre><a class="linenr" href="#{lineid}" id="{lineid}">{linenumber}</a></pre></td>
     <td><pre>{line|escape}</pre></td>
   </tr>'
-difflineplus = '<span style="color:#008800;"><a class="linenr" href="#{lineid}" id="{lineid}">{linenumber}</a> {line|escape}</span>'
-difflineminus = '<span style="color:#cc0000;"><a class="linenr" href="#{lineid}" id="{lineid}">{linenumber}</a> {line|escape}</span>'
-difflineat = '<span style="color:#990099;"><a class="linenr" href="#{lineid}" id="{lineid}">{linenumber}</a> {line|escape}</span>'
+difflineplus = '<span class="difflineplus"><a class="linenr" href="#{lineid}" id="{lineid}">{linenumber}</a> {line|escape}</span>'
+difflineminus = '<span class="difflineminus"><a class="linenr" href="#{lineid}" id="{lineid}">{linenumber}</a> {line|escape}</span>'
+difflineat = '<span class="difflineat"><a class="linenr" href="#{lineid}" id="{lineid}">{linenumber}</a> {line|escape}</span>'
 diffline = '<a class="linenr" href="#{lineid}" id="{lineid}">{linenumber}</a> {line|escape}'
 
 comparisonblock ='

mercurial/templates/monoblue/map

@@ -100,9 +100,9 b" annotateline = '"
     </td>
     <td class="source">{line|escape}</td>
   </tr>'
-difflineplus = '<span style="color:#008800;"><a class="linenr" href="#{lineid}" id="{lineid}">{linenumber}</a> {line|escape}</span>'
-difflineminus = '<span style="color:#cc0000;"><a class="linenr" href="#{lineid}" id="{lineid}">{linenumber}</a> {line|escape}</span>'
-difflineat = '<span style="color:#990099;"><a class="linenr" href="#{lineid}" id="{lineid}">{linenumber}</a> {line|escape}</span>'
+difflineplus = '<span class="difflineplus"><a class="linenr" href="#{lineid}" id="{lineid}">{linenumber}</a> {line|escape}</span>'
+difflineminus = '<span class="difflineminus"><a class="linenr" href="#{lineid}" id="{lineid}">{linenumber}</a> {line|escape}</span>'
+difflineat = '<span class="difflineat"><a class="linenr" href="#{lineid}" id="{lineid}">{linenumber}</a> {line|escape}</span>'
 diffline = '<a class="linenr" href="#{lineid}" id="{lineid}">{linenumber}</a> {line|escape}'
 
 comparisonblock ='

mercurial/templates/static/style-gitweb.css

@@ -84,6 +84,9 b' span.logtags span.bookmarktag {'
 	background-color: #afdffa;
 	border-color: #ccecff #46ace6 #46ace6 #ccecff;
 }
+span.difflineplus { color:#008800; }
+span.difflineminus { color:#cc0000; }
+span.difflineat { color:#990099; }
 
 /* Graph */
 div#wrapper {

mercurial/templates/static/style-monoblue.css

@@ -260,6 +260,10 b' div.diff pre span {'
   font-size: 1.2em;
   padding: 3px 0;
 }
+span.difflineplus { color:#008800; }
+span.difflineminus { color:#cc0000; }
+span.difflineat { color:#990099; }
+
 td.source {
   white-space: pre;
   font-family: monospace;

tests/test-hgweb.t

@@ -332,7 +332,7 b' static file'
 
   $ "$TESTDIR/get-with-headers.py" --twice localhost:$HGPORT 'static/style-gitweb.css' - date etag server
   200 Script output follows
-  content-length: 5262
+  content-length: 5372
   content-type: text/css
   
   body { font-family: sans-serif; font-size: 12px; border:solid #d9d8d1; border-width:1px; margin:10px; }
@@ -421,6 +421,9 b' static file'
   	background-color: #afdffa;
   	border-color: #ccecff #46ace6 #46ace6 #ccecff;
   }
+  span.difflineplus { color:#008800; }
+  span.difflineminus { color:#cc0000; }
+  span.difflineat { color:#990099; }
   
   /* Graph */
   div#wrapper {