Merge gcodeInterpreter optimizations from daid/Cura
Don't store layers or path points to save memory
Increase progress callback to every 1000 lines.

The processor handles 2500 lines per second on a 700MHz pi so as a baseline
that's still 2.5 updates per second.
Enforces a new first-run setup wizard for access control to be run and forbids running OctoPrint as root unless a special command option is supplied

The dialog also informs about the risk of unauthorized strangers (mis)using the printer if an unsecured OctoPrint installation is made available on the internet.
Only enable "Keep Enabled" button if data entered into form is valid. Also changed the wording a bit here and there.
And a robots.txt for good measure...
Removed commented out and unused code
Merge branch 'CapnBry-gcodeinterpreter-upstream' into devel
Refactored ui.js into single files, cleaned up js folder

TODO: minimizer for merging all files belonging to the actual app into one
Allow sending temperature updates with enter

Also some refactoring.

Closes #208.