Minor fixes for Drawing plugin
Minor fixes for Drawing plugin

- removed duplicate "Coord" parameter box.
- selecting a new draw type now puts the canvas in draw mode

ejeschke/ginga,pllim/ginga,ejeschke/ginga,naojsoft/ginga,pllim/ginga,naojsoft/ginga,pllim/ginga,naojsoft/ginga,ejeschke/ginga