0.0.2.3 - More custom cmd fixing

Thanks to https://github.com/puterboy for his bug hunting in this release.

New:

• [Feature Request] custom execute execution in bash #95

Bug fixes:

• BUG: Histogram length doesn't work for faster sampling rates #94
• BUG: Sensor error/offline requires restart of octoprint #93
• "Command" should have a timeout associated with it... #88