veyron/tools/playground: Put more info in the Events.

The events now have the file, message, timestamp, and stream
(stdout/stderr).

The playground client support is here:
https://github.com/veyron/veyron-www/pull/37

Change-Id: I2f0f5bcaa809767ece06252319dd097c0dd3b570
7 files changed
tree: 5d24f3885faf2d73288bc620b00808de3bf2f64f
  1. lib/
  2. profiles/
  3. runtimes/
  4. security/
  5. services/
  6. tools/