templates: differentiate between partial and full topic name

In order to support sub-topics, we need to support linking to a full
topic name while displaying the base topic name. Change the {helpentry}
template to grab the display name from an optional seperate variable
(which will be defined in a future patch).

mercurial/templates/gitweb/map

@@ -14,7 +14,7 b' helptopics = helptopics.tmpl'
 helpentry = '
   <tr><td>
     <a href="{url|urlescape}help/{topic|escape}{sessionvars%urlparameter}">
-      {topic|escape}
+      {if(basename, '{basename|escape}', '{topic|escape}')}
     </a>
   </td><td>
     {summary|escape}

mercurial/templates/monoblue/map

@@ -14,7 +14,7 b' helptopics = helptopics.tmpl'
 helpentry = '
   <tr><td>
     <a href="{url|urlescape}help/{topic|escape}{sessionvars%urlparameter}">
-      {topic|escape}
+      {if(basename, '{basename|escape}', '{topic|escape}')}
     </a>
   </td><td>
     {summary|escape}

mercurial/templates/paper/map

@@ -15,7 +15,7 b' helptopics = helptopics.tmpl'
 helpentry = '
   <tr><td>
     <a href="{url|urlescape}help/{topic|escape}{sessionvars%urlparameter}">
-      {topic|escape}
+      {if(basename, '{basename|escape}', '{topic|escape}')}
     </a>
   </td><td>
     {summary|escape}