Release specifically for the UofA addressing numerous bugs:

• Prevent contents of Selectize input from being cleared when focus is lost
• Allow text selection via mouse dragging by making the Selectize input as wide as it can be
• Prevent dropdown from closing if a header is clicked on
• Allow the filter option to be set for Sifter
• Amend scrolling to compensate when headers are present in the dropdown
• Use silent flag to determine whether to fire the relevant callback
• If the Selectize input is already focussed, unset any active item
• Fix ability to ignore hovering
• Minor comment updates
• Fix indentation