powerd++ 0.4.0 release

This release adds support for systems that have HT disabled and load
recording while a powerd is running.

• If HT is disabled the number of columns provided kern.cp_times
  is inconsistent with the number of cores reported hw.ncpu, this
  update allows powerd++, loadrec and loadplay to handle this gracefully
  instead of refusing to start
• Allow loadrec to record loads while a powerd is running, due to
  this pre 0.4.x versions of loadplay can not play new load recordings
  correctly
• Add feature flags to load recordings
• Add loadplay support for the new load recordings
• loadplay reports loads in MHz
• Remove redundant outputs from loadplay

This release is thanks to a bug report by Crest, improvements between
rc1 and this release are thanks to a report by miwi. Testing of rc1
was provided by Yamagi, miwi and mr44er. Natuarally all mistakes
and errors that remain are mine.