Added

• Add new set of system icons:
  • electricity
  • flow
  • length
  • measure
  • pressure
  • save
  • temperature
  • voltage
  • Several media-related icons: backward, forward, next, pause, play, record, previous, stop.
• Add indeterminate checkbox and radio button status.
• Add map pattern.
• Add new base color (base950).

Changed

• Improve theming explanation, especially for dark theme.
• Improve color variables description for theming.
• Improved breadcrumb pattern for Firefox browsers.
• Update browser support, remove deprecated IE 11 browser.