includeFeatherRuntime

Adds "uk.co.nickthecoder.feather.runtime" to impliedImportPackages. Adds "uk.co.nickthecoder.feather.runtime.Extensions" and "uk.co.nickthecoder.feather.runtime.Print" to impliedImportClasses

If you turn this on, ensure your project also include the feather-runtime jar in your classpath at compile-time and runtime.