(set-justification): New function.

(set-justification): New function.
(set-justification-{none,left,right,full,center}): New functions.
(fill-region-as-paragraph, fill-region, justify-current-line): New
arg NOSQUEEZE defeats normal removal of extra whitespace.
(fill-region-as-paragraph, fill-region)
(fill-nonuniform-paragraphs, fill-individual-paragraphs):
Arg JUSTIFY-FLAG (JUSTIFYP) renamed to JUSTIFY.
(fill-region-as-paragraph): Obey left-margin; fill-prefix starts
after left-margin.  Disable filling if JUSTIFY == none, but indent to
margin anyway.
Adaptive-fill removes text-props from fill-prefixes it finds.
Adaptive-fill no longer has to notice left-margin: std fill does that.
Use fill-column and canonically-space-region functions.
(canonically-space-region): New fn split from fill-region-as-paragraph.
(fill-region): New args NOSQUEEZE (as above) and TO-EOP.
(default-justification): New variable.
(current-left-margin, fill-column, justification): New functions.
(fill-paragraph): Use fill-region-as-paragraph when possible.
(justify-current-line): New arguments; different kinds of
justification handled.  Uses left-margin and fill-column functions.