(fill-move-to-break-point): Skip white space

(fill-move-to-break-point): Skip white space
_before_ checking to see if we're hitting the margin.
(fill-region-as-paragraph): Don't fiddle with the undo-list any more:
it's now done by the C primitives.  Don't use narrowing.
Reorganize the line-breaking part of the code to simplify the control
flow and make it work in the absence of narrowing.
(fill-region): Don't use narrowing.