[Swftools-common] small improvment required

[jean-michel.voicechat_fan]

hello matthias
i suggested you a very small & simple change  which can  be usefull in 
swfextract.c

line 9  in function handlejpeg replace filename ="output.jpg" ; by 
filename =name  ;

like that each jpeg file  will be named differently picXX.jpg
same in line 85 in function handlelossless ( for png files )

replace filename="output.swf" by filename = name ;

each png file will be named  by picXX.png


XX is the number shown in the no option swfextract command