Gridkit Extended Release

A nearly full release of Gridkit is available as alpha code. We've tried to include as much as we could in this release. There are new interaction types: notably group communication and tuple spaces. There are new overlays: chord, scribe, scamp, shortest path tree. There is also some discovery framework code.

This is alpa code at the moment and we are working on a stabler release at this time. However, we hope bugs are at a minimum. In addition, we will be adding dependability services (the source code for this is in the release but is turned off).