serialize image service layer
added rendering rule example
added links to new example pages and updated readme
Merge pull request #5 from tomwayson/img-svc

Added partial support for image services
Bump version to 3.9, remove IE meta tag, fix JSHint errors.
Update comment in map-cereal.js to indicate that ArcGISImageServiceLayer is supported.
Add missing parens to call to SimpleLineSymbol.