*) add hotkey for setting the grid origin as 'S', in board editor, module editor.
*) re-position the function interface for cursor movement from BASE_SCREEN into
class EDA_DRAW_FRAME. This is a prelude to getting rid of BASE_SCREEN or
splitting it up.
Should allow Pcbnew code easier to change and Gerbview code more understandable and easier to maintain.
Code cleaning (remove dead code, add comments).
Minor other enhancements.
jean-pierre charras
Dick Hollenbeck
Lorenzo Marcantonio