v1.20.0

• fixed signal sync gui: now correctly handles resizing and plot limits changes
• added dynamic validation: a PsychoPy script that shows validation fixation targets one at a time
• plane.Plane and validation.Plane: now checks markers and targets are on the plane, and issues intelligible error messages if not
• fixed up internals of popups: reworked mechanism for button activation through keypress, and ensured it takes into account whether button is disabled (then key press should do nothing)
• filepicker: reset scroll upon navigation, reselect activated item upon going forward/backward in history
• individual marker config: size is now optional, can also create markers that are just flagged for presence, not pose
• gaze overlay video: can now control looks of gaze marker; added support for 3D gaze point in world
• some other small enhancements