croupier: Add SyncbaseEcho

Modified the Makefile and Croupier organization slightly to add a new
'game' called SyncbaseEcho.

SyncbaseEcho and SyncbaseEchoImpl essentially do what the original Sky
example in roadmap/mojo/syncbase does.
Note: These had to be split up, or else make test wouldn't work anymore.
Some of the embedder code won't run in a stand-alone VM.

To run with mojo_shell use `make start-with-mojo` instead of the usual
`make start` or `make install`. It also doesn't run on Android at the moment.

Improved the Makefile too, by making things PHONY-er.

Change-Id: I7e7a3d921e02b587b1d7047633fbcc84b1094892
16 files changed
tree: 2781523dd0c9b78a28d1f123a8c21289a734164d
  1. lib/
  2. test/
  3. .gitignore
  4. Makefile
  5. mojoconfig
  6. pubspec.yaml
  7. README.md
README.md

This is the basic Getting Started with Sky + some Widgets.

To run this, just do ./packages/sky/sky_tool start

when your phone is connected. Add --install to the end if this is the first run.

You may also want to debug any problems. Use dartanalyzer. dartanalyzer lib/main.dart