Page layout editor: Add bitmap items to the page layout existing items.
Now a bitmap image can be added to a page layout description. Currently the bitmap is expected having a 300 ppi definition.
Note: not all plotters can plot a bitmap, and in this case the bounding box is plotted instead of the bitmap
*) 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.
jean-pierre charras
Dick Hollenbeck
Camille Delbegue