add python 2.5 compatibility for multi app (with statement)
add python 2.5 compatibility for multi app (with statement)

kaiCu/mapproxy,camptocamp/mapproxy,kaiCu/mapproxy,Anderson0026/mapproxy,geoadmin/mapproxy,drnextgis/mapproxy,drnextgis/mapproxy,mapproxy/mapproxy,mapproxy/mapproxy,olt/mapproxy,camptocamp/mapproxy,procrastinatio/mapproxy,faegi/mapproxy,vrsource/mapproxy,olt/mapproxy,faegi/mapproxy,vrsource/mapproxy,Anderson0026/mapproxy,procrastinatio/mapproxy,geoadmin/mapproxy