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