add minzoom and maxzoom for openmapsurfer layers
Fix #96 : add Hydda tiles from openstreetmap.se
Merge pull request #97 from leaflet-extras/hydda

Fix #96 : add Hydda tiles from openstreetmap.se
add Hydda.RoadsAndLabels to overlays list
bump version
Merge branch 'master' of github.com:leaflet-extras/leaflet-providers into gh-pages