added validate_sld_version method, sld_version param is now a non_strict_param
added validate_sld_version method, sld_version param is now a non_strict_param

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