Improved OS X integration

[phodge]

Make use of:

• https://github.com/julienXX/terminal-notifier

• https://github.com/jaredks/rumps

• Need to have a proper config mechanism for turning this behaviour on/off

• When update completes successfully, send a notification

• When update fails, send a notification which also opens an error file in textedit

• allow installing a timer (how?) which prompts the user to kick off an update periodically

• if using rumps, provide menu buttons to for:

  • run a full update
  • run particular sections
  • turn the timer on/off

• can we get the yes/no prompts to show up in OS X?

• can we get the homely update to happen in a terminal window that the user can watch?