Merge pull request #14 from tombatossals/master

Merge with original
Init layercontrol directive
Add opacity control for layercontrol directive
More layer control capabilities
Add LayerGroup support for layercontrol directive
Finish opacity control for layercontrol directive
Add container and legend to overlays in layercontroldirective
Fix #289, #431 issues, and changes on control-draw example
Fix #349 issue
Merge with original
Add order option to layercontrol directive
Merge pull request #463 from elesdoar/master

Fix errors and introducing layer control