Added tooltip for 'S' and 'W' in the top page for showing what it is.

git-svn-id: https://hudson.dev.java.net/svn/hudson/trunk/hudson/main@12796 71c3de6d-444a-0410-be80-ed276b4c234a

core/src/main/resources/lib/hudson/projectView.jelly

@@ -23,8 +23,8 @@
                     <x:attribute name="style">margin-top:0px; border-top: none;</x:attribute>
                 </j:if>
                 <tr style="border-top: 0px;">
-                    <th>S</th>
-                    <th>W</th>
+                    <th tooltip="${%Status of the last build}">S</th>
+                    <th tooltip="${%Weather report showing aggregated status of recent builds}">W</th>
                     <th initialSortDir="down">${%Job}</th>
                     <th>${%Last Success}</th>
                     <th>${%Last Failure}</th>