z-Offset script
View Model
calibration_zOffset
More functionality z-offset script
CSS changes etc.
Added old value and redid calibration structure.
Merge branch 'zOffset' into LilyPrint
Merge branch 'zOffset' into LilyPrint

Conflicts:
	src/octoprint/static/js/app/viewmodels/zoffset.js
	src/octoprint/templates/dialogs.jinja2