1. Rework how communications with tag occur.
a. bitstream to be sent to the tag is now fully pre-generated.
b. bits sent and received are logged with start / end times.
2. Support built-in `hw dbg` for controlling verbosity of debug output
The new bitstream generation and logging has exposed a surprising legacy behavior ... each of the command that sent additional data (beyond the command) were:
* inserting an extra RM zero bit
* force-enabling command parity is used
This was not expected. However, this PR maintains the behavior of the existing code.
TODO: Root-cause why the third RM bit is needed. Fix code to remove that hack.
TODO: change the arm/client interface to ONLY use arrays of bytes, with well-defined content endianness, to avoid this problem.
Also:
* common.h: Increase safety of some of the macros.
Parenthesizing the macro parameters ... a best practice.
* firmware: partially-tracked source of "extra bits" messages.
Add a TODO comment for further study.
* Improve reliability of `lf em 4x70 writekey`
Authenticate w/new key after it is written.
Particularly important for glass modules,
or other tags with weaker coupling.
