XSL Tree Plotting

This is based on Jirka Kosek's tools, built in a way that is easy to install and use. By omitting the first stage, it can be readily adapted to directly plot trees from a known XML file, which would be useful for our GP output processing project. Steps to use:

1. Download this tarball containing example files and the xsl script
2. Create an XML file in (a variant of) Kosek's format
3. Place htotree.xsl in a suitable location
4. Download and install Saxon. Please note: you must either use Saxon 6 (an old version that incorporates EXSLT), or install EXSLT into later versions yourself, or upgrade the whole system to use XSL 2
5. Create a shell script to call saxon (you can adapt this one to point to the right places on your machine)
6. Run the script, and point your browser at the resulting output file (firefox, safari and opera all work, I gather internet explorer has some bugs in its svg implementation which may call it to fail, though there are patches around on the web to adapt the xslt to work with explorer als)