Add logging and tracing
Logging:
- Added configuration in CLI
- Added log message to all major functions (e.g. those that interact with the boards, or can take a significant amount of time)
Tracing:
- Record start time and duration of all key high-level procedures in this codebase, plus start time & duration of HERD commands & transitions
- Write that to a file in google's trace event format if
TRACE_EVENT_FILE
environment variable is defined