Remove the map renderers option
Use the renderer map option in the examples
Rename ol.render.IRender to ol.render.IVectorContext
Update examples to use vectorContext property in render events
Merge pull request #1657 from elemoine/renderer

Do not expose both renderer and renderers options
Merge pull request #1655 from twpayne/vector-context

Rename IRender to IVectorContext
Allow ol.Map renderer option to be a string
Use string instead of ol.RendererHint enum in examples
Don't export ol.RendererHint
Allow ol.Overlay positioning option to be a string
Use string instead of ol.OverlayPositioning enum in examples
Don't export ol.OverlayPositioning
Allow ol.control.ScaleLine units option to be a string
Use string instead of ol.control.ScaleLineUnits enum in examples
Don't export ol.control.ScaleLineUnits
Allow ol.source.Source state option to be a string
Don't export ol.source.State
Allow ol.source.{Image,Tile}WMS serverType option to be a string
Don't use ol.source.wms.ServerType enum in examples
Remove no-longer-needed typecasts