Add catman, makewhatis functionality.  Print an error if the whatis database
is missing.

@@ -50,10 +50,11 @@
                 builtin.1                       \
                 cal.1                           \
                 calendar.1                      \
                 cancel.1                        \
                 cat.1                           \
+                catman.1                        \
                 cd.1                            \
                 cdrw.1                          \
                 checknr.1                       \
                 chgrp.1                         \
                 chkey.1                         \