Added comment info to abi_checker.xml.in so we'll remember how to use the abi checker.
Added comment info to abi_checker.xml.in so we'll remember how to use the abi checker.

OPENDAP/libdap4,OPENDAP/libdap,OPENDAP/libdap,OPENDAP/libdap4,OPENDAP/libdap4,OPENDAP/libdap4,OPENDAP/libdap4,OPENDAP/libdap,OPENDAP/libdap4,OPENDAP/libdap