Self-contained builds

[Randall Hauch]

Our build now uses a local installation of WPILib; see this issue and PR for details and background on the subject. This work has been completed and merge into the codebase.

That means that when you use Git to fetch the latest code with these specific changes, you'll first need to run `ant test` from the main directory of the codebase before you refresh your Eclipse projects. By running `ant test`, our build will download and install the correct version of the WPILib into the location that the Eclipse projects now expect. So after you do this, you can refresh your Eclipse projects, and they should work as normal. (This is documented in the repository's README file.)

What happens if you refresh Eclipse first? You'll get multiple errors that look like:

Project 'strongback' is missing required library: '/libs/wpilib/java/current/lib/WPILib.jar'

If you ever get this error, simply run `ant test` from the command line, and then refresh your Eclipse projects.