add export image button to plasmid map.
Display the current selection
Added mouse events. Splitting up PMD into init, update, and draw.
Live updating
Draggable selection from plasmid map
Added line markers
Added name to annotations on canvas.
Make everything variables
Merge branch 'master' into pmZoom
Show plasmid map after merge
Rotatable plasmid map. Added simple2d.js to deal with canvas not storing transform matrices.
Zoom and rotate both working.