All: Fix an usually unwanted behavior in kicad: When closing a dialog (mainly ERC, DRC and recently a component selection by the library viewer on a double click) the mouse release left button event (which is seen by the parent after closing the dialog, becuse it is actually made in the parent) generate an unwanted command (item selection, component place ...)
This event can be now skipped if needed by calling  EDA_DRAW_FRAME::SkipNextLeftButtonReleaseEvent() from the dialog.
Very minor other fixes