[traceutil] Stream zedmon to JSON; merge into HTML

- actions: convertTrace() accepts multiple files

  - Pass additional zedmon file when -zedmon specified

- Temporary: Local copy of minimal tracing event structs required for
  zedmon trace

- Hardcoded zedmon pseudoprocess PID: "zedm" ASCII

- Channel-based zedmon interface

  - On run(): Stream CSV into structs, then JSON bytes

    - Return channels for data and errors

  - On stop(): Stop streaming and cleanup

Change-Id: Ibf3e9693714d310f62c99aec7f10474a571fc829