clean up nugen's d/l script and add a warning to clsim's

DO NOT copy these scripts into other projects.

stop scripts from blowing up in your face if /bin/sh is not bash
make scripts find md5 on Darwin
'Sonic' Smith can't help us :(


git-svn-id: http://code.icecube.wisc.edu/svn/projects/clsim/trunk@119202 16731396-06f5-0310-8873-f7f720988828