Fix live sync.

The refactor to use StructOpt instead of plain Clap had some absolute
vs relative path issues that slipped through. This commit adds getters
to each StructOpt struct that exposes an explicitly absolute version
of each path value.

src/cli/serve.rs

@@ -28,7 +28,7 @@ pub fn serve(options: ServeCommand) -> Result<(), ServeError> {
 fn serve_inner(options: ServeCommand) -> Result<(), Error> {
     let vfs = Vfs::new(RealFetcher::new(WatchMode::Enabled));
 
-    let session = Arc::new(ServeSession::new(vfs, &options.project));
+    let session = Arc::new(ServeSession::new(vfs, &options.absolute_project()));
 
     let port = options
         .port