universal figtree bash script

[schellt]

To have figtree in your $PATH you included a bash script that executes the jar file. Since there is no absolute path, it will not find figtree.jar. To avoid that every user needs to edit the script and write the absolute path I allowed myself to find the location of the bash script within itself.
The relative paths from the bash script to figtree.jar are different in the cloned repository and the release. The script should be like this to work within a release:

#!/bin/sh
FIGTREEPATH=`realpath $0 | sed 's/figtree$/\.\.\//'`
java -Xms64m -Xmx512m -jar ${FIGTREEPATH}lib/figtree.jar "$@"