add res_range support for SRS and resolution conditional layers
add res_range support for SRS and resolution conditional layers

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