Compile XML processing regular expression only once.
Compile XML processing regular expression only once.

Requests per second from ~95 to ~98 with a "standard" test.

manueltimita/Windshaft-cartodb,CartoDB/Windshaft-cartodb,CartoDB/Windshaft-cartodb,manueltimita/Windshaft-cartodb,UCL-ShippingGroup/Windshaft-cartodb,UCL-ShippingGroup/Windshaft-cartodb,CartoDB/Windshaft-cartodb,CartoDB/Windshaft-cartodb,UCL-ShippingGroup/Windshaft-cartodb,manueltimita/Windshaft-cartodb