[Pkg-postgresql-public] postgresql-common calling external programs with full path

[Peter Eisentraut]

pg_createcluster calls pg_ctlcluster as '/usr/bin/pg_ctlcluster',
whereas pg_dropcluster calls only 'pg_ctlcluster'.  On the other hand,
pg_dropcluster calls '/bin/rm', but nothing else calls basic system
utilities with the full path.  I think specifying the full directory is
unnecessary and should be removed in both of these cases.  Comments?