Make drag ghost exact same dimension as the original / dragged feature.

Previously drag ghost of exons would sometimes be 2-4px less in width because
of left-edge-match and right-edge-match classes.

Signed-off-by: Anurag Priyam <anurag08priyam@gmail.com>
Sometimes the entire transcript would be highlighted after resizing an exon.

Prevent that from happening.

Signed-off-by: Anurag Priyam <anurag08priyam@gmail.com>