Add project status disclaimer

[tyvsmith]

In an effort to provide more transparency to project state, Add the appropriate disclaimer on the top of the README.

Some examples as follows:
-This project is a technical snapshot and will not be kept in sync.
-This project is deprecated and not maintained.
-This project is experimental and the APIs are not considered stable.
-This project is stable and being incubated for long-term support
-This project may contain experimental code and may not be ready for general use. Support and/or new releases may be limited.

[benpious]

Do we want to put this on the project itself or individual releases?

I'm not putting a copy-pastable snippet for integrating this into an app currently -- prospective users will have to pick from the list of releases.

I think that works better, since I probably want to know what this project is before I think about using it.