Refactor + fixes

[OnceUponALoop]

• Fixed proxy config
• Removed dead code (coachgui)
• Removed Coach GUI
• Busy dialog on startup
• Busy dialog while player loads

[OnceUponALoop]

@aqw Check it out and let me know what you think, my plan was to clean up the kodi17 code before moving on to kodi18 dev.

It looks like a ton of changes but it boils down to the listed changes and

• Move pigskin init into GUI class
• Pull static functions out of GUI class

[aqw]

@OnceUponALoop Thanks a bunch for the PR!

I've only skimmed through thus far, but this looks great. It removes a whole load of ugly. /Much/ appreciated.

I've given it a quick test, and everything that i touched worked. :-)

I'll give this a closer read later tonight. Thanks again! :-)

---Alex