doc: pimage options moved to pimage
doc: added/implemented arrowhead options on pline, polyline, path objects
demos: textproperties

-fontweight normal|bold
-fontslant normal|italic|oblique
-fill
-filloverstroke
-fillopacity
-stroke
-strokewidth
-strokeopacity
demos: ptext: added -textanchor
demos: text bold/italic
demos: added imagetint
demos: pimage: added -interpolation {none|fast|best} option
demos: pimage: -srcregion
demos: added example for pimage -width/-height and -fillopacity
demos: some files contained old Mac line endings (CR only)
demos: test linear gradient and -fillopacity
demos: added pimage: -anchor demo
demos: added gradientsalpha demo
TMP-imagealpha
demos: added arrowhead demos