CDK-451: View isReady / signalReady

This PR builds on https://github.com/kite-sdk/kite/pull/98 and https://github.com/kite-sdk/kite/pull/99 adding support for isReady / signalReady on Views.
I'll take a look at that -- I assume you must be referring to org.kitesdk.data.spi.filesystem.PathConversion?  I probably just haven't been working in the code long enough to have known about that.