Add tooltip to attribute type

Author: amomchilov

lib/rdoc/generator/template/darkfish/class.rhtml

@@ -96,8 +96,8 @@
         <div class="method-heading attribute-method-heading">
           <a href="#<%= attrib.aref %>" title="Link to this attribute">
             <span class="method-name"><%= h attrib.name %></span>
-            <span class="attribute-access-type">[<%= attrib.rw %>]</span>
           </a>
+          <span class="attribute-access-type" title="<%= attrib.definition %>">[<%= attrib.rw %>]</span>
         </div>
 
         <div class="method-description">