fixed 404 errors
Fix bringToBack: pane variable undefined

Changed pane by this._pane
Merge pull request #2 from bielfrontera/patch-1

Fix bringToBack: pane variable undefined
added support for z-index and opacity
Update Readme.md
cleaned up
Merge branch 'master' of https://github.com/oliverheilig/Leaflet.NonTiledLayer