Updating install.sh script for use behind firewalls.

commit fdda14d8c2ff4ea7525ec025d3855489e0410041
Author: Jay Proulx <jason.proulx@pollensoft.com>
Date:   Wed May 29 12:24:50 2013 -0400

    git:// won't work behind some firewalls.  We don't need write access, https will suffice.