install_picard.sh: updated to handle different download locations depending on requested Picard version.
install_picard.sh: supply either a version number or an existing zip archive to install from.
install_picard.sh: don't use existing archive file unless explicitly specified.
install_galaxy.sh: add placeholder for setting master API key.
Merge branch 'master' of github.com:pjbriggs/bioinf-software-install