am 2d0a6ca2: Merge change 4227 into donut

Merge commit '2d0a6ca27c6f75eb0ec881fe4ad0b4f478d941c0'

* commit '2d0a6ca27c6f75eb0ec881fe4ad0b4f478d941c0':
  nexctl: Refactor so Nexus can be tested from scripts easily.
  libsysutils: Move to a null terminated string protocol using space as a field separator.