Multiple choice images & import and export

This release adds the following features:

• Multiple choice images
• Import and export: make it easier to collaborate by allowing a "minimal" export. The 360 video is not exported, making project sizes much smaller

Quality of life changes

• Show local disks and special folders in the explorer panel
• Highlight current row in the timeline
• Interaction points need to be active for at least 1 second. Previously, you could make an interaction point last so shortly that it became "invisible" in the timeline
• Change timeline item button visibility. Prevents a number of bugs
• The Esc button now closes most pop up windows.