Package metadata

[Jeremy Kahn]

I just pushed an update to dev-server.js - it now traverses all packages and builds the main menu from metadata files.  I created a pretty simple convention: A Pine package must have pine-package.json in its root directory, and it should look like this.  This is just the beginning of how package files will work, we can add more features as we need them.  I'll document this in the wiki soon.