LDAP shell

The ldapsh functions rename and mkdir conflict with the
perl builtin functions for no good reason. The
functionality is already available in ldapsh under
different names.

I was burnt by this while upgrading ldapsh at a client
installation. The client has a largish user
adminstration application built on top of ldapsh, which
also does things like create home directories and
distributing automaps.

Yes, I know we can use CORE::<function> to get the
right one for manipulating the file system, but I think
it's a bad idea in principle to override the builtin
functions of perl. Who knows which function will be
overridden next, and it quickly becomes unfeasible to
prepend CORE:: to every function call to future-proof
the code.

This patch removes the offending functions from LDAPsh.'

Comments?