Add CAS server startup to CI test script.

Also add URL generation tasks for CAS and ladle-controlled LDAP.
JRuby-compatible spawn options.

This doesn't really do the same thing as the previous form, and it
doesn't actually do anything in JRuby 1.7.x.

However, the [:out, :err] => "/dev/null" form causes a program abort in
JRuby 1.7.x.  This form doesn't.