Disable monitoring if it is not explicitly enabled

XWiki Enterprise\webapps\xwiki\WEB-INF\xwiki.cfg file contains the following lines:

#-# Enable light monitoring of the wiki performance. Records various statistics, like number of requests processed,
#-# time spent in rendering or in the database, medium time for a request, etc. Disable for a minor increase of
#-# performance and a bit of memory.
# xwiki.monitor=1

This is quite misleading because although xwiki.monitor=1 is commented out XWiki still monitor requests.
To actully turn it off one has to put

xwiki.monitor=0

Monitoring shall be turned off if xwiki.monitor setting is not defined (i.e. is commented out).

Please find attached a proposed patch (should be applied to http://svn.xwiki.org/svnroot/xwiki/platform/core/trunk)