* pandora_userguide.xml, pandora_chapter*: Many changes to use PNG
graphics instead .GIF. Many format changes.
* many *.gif - > *.png: .GIF files deleted and replaced by .PNG.
git-svn-id: https://svn.code.sf.net/p/pandora/code/trunk@204 c3f86ba8-e40f-0410-aaad-9ba5e7f4b01f
slerena