icon files renamed in wiki

[Simon Michael]

Following discussion on irc, I have added a .png suffix to all the Icon* 
and Pic* image files in the wiki. This is so that the moin formatting 
rules can recognize the images and display them. It's helpful for other 
software too.

The old filenames are still there as well; I propose to delete those a 
week from now. So references to these images throughout the wiki need to 
be updated. Many hands will make light work! Please fix one today, like 
this:

0. go to http://ubuntulinux.org/wiki , log in
1. pick an image name from the list below
2. click wiki search and enter the image name (or use the site search)
3. click a result
4. edit the page, add .png to all occurrences of the image name, save

This will allow the images to be used in moin markup mode as follows:

display an image:

http://ubuntulinux.org/wiki/PicDocs.png

display image and link it:

[http://ubuntulinux.org/wiki http://ubuntulinux.org/wiki/PicDocs.png]

The full url is required. Finally, I don't know for sure that these are 
all png files; I just added .png.