Fix handling of '&' symbols in JUnit XML

Without this change whenever  URLs with '&' symbol appears in phpunit output, it triggers warning and URL is corrupted in Jenkins.

Example URL:
http://test.site.com?key=1419318842&ip=0i1BxHBaShQueFNYFQaA3IbyAJC3HncWngeY2hZdEy3bSTFOkeXUzbusMUyiisAPAgoc50Ms-wuTS_rWwUHLvPNzFchl8ebXm3ljF83mfzxX98SaPLzWtoyMQauIwHWqKknjtRxRI1flde3ovN7kdQ&im=image/png&o=&cd=inline

Error in console:
 [exec] #2 /var/www/optimalprint-trunk/internal/SL/Test/Functional/Page/Category/CategoryDesktopPHP Warning:  DOMDocument::createElement(): unterminated entity reference ip=0i1BxHBaShQueFNYFQaA3IbyAJC3HncWngeY2hZdEy3bSTFOkeXUzbusMUyiisAPAgoc50Ms-wuTS_rWwUHLvPNzFchl8ebXm3ljF83mfzxX98SaPLzWtoyMQauIwHWqKknjtRxRI1flde3ovN7kdQ&im=image/png&o=&cd=inline