hex2bin is working but device must be connected

- bin2hex is not implemented
ignore device init for hexbin conv
implement bin2hex and add default cmd settings

- implement bin2hex, tested hex2bin > bin2hex and end up adding an
  empty byte (0xff) at the end of conversion but otherwise works
- not sure that command settings structures are actually initialized
  so added section for setting defaults
update authors / changelog
Merge branch 'binhex_convert'