feature: use google-sitemap xml as source for target-urls

[typoworx-de]

Feature-Request:
It would be awesome to simply have a new parameter making it possible to give the tool a sitemap.xml file|url to parse all testing URLs from. I know it's possible using grep and some external tools as well. But this would make the whole thing 'more handy' :-)

[infojunkie]

For what it's worth, here's how I handle sitemaps:

wget -q $BASE_URL/sitemap.xml -O sitemap.xml
xmllint --xpath "//*[local-name()='loc']/text()" sitemap.xml >> urls.txt

and then run siege against this file.