look for the workdir script and run it if we find it

--HG--
extra : convert_revision : svn%3A98f53aa3-d424-0410-b225-a548b0275c4d/Projects/virtualenvwrapper/trunk%401353

Author: dhellmann

virtualenvwrapper_bashrc

@@ -87,5 +87,9 @@ function workon () {
         return 1
     fi
     source "$activate"
+    if [ -f "$WORKON_HOME/$env_name/bin/workdir" ]
+    then
+        source "$WORKON_HOME/$env_name/bin/workdir"
+    fi
 	return 0
 }