Zoom in happens too early #14
Description
On some systems (need to figure out the actual conditions under which this occurs) zoom in occurs as soon as the user begins to draw the zoom box (while left mouse is still being held)
We want the zoom to occur only after the left mouse button has been released.
The current version will no longer support drawing zoom boxes and will handle zooming by drawing a zoomed in sub-panel of overlapping vowels when the user clicks on overlapping vowels.
Question: is the temporary solution sufficient or do we want to figure out the source of the current bug and fix it?