Add SimoxUtility to doc generation. Enable internal search engine

doc/Doxyfile.in

@@ -1204,7 +1204,7 @@ MATHJAX_EXTENSIONS     =
 # typically be disabled. For large projects the javascript based search engine 
 # can be slow, then enabling SERVER_BASED_SEARCH may provide a better solution.
 
-SEARCHENGINE           = NO
+SEARCHENGINE           = YES
 
 # When the SERVER_BASED_SEARCH tag is enabled the search engine will be 
 # implemented using a PHP enabled web server instead of at the web client