* dumpv4.c: new file. New command dump_v4db which creates a v4

	* dumpv4.c: new file. New command dump_v4db which creates a v4
	slave dump out of a v5 database, leaving out any keys which aren't
	using v4 salt, and any keys that aren't for the current
	realm. Reencrypts using v4 master key, synthesizes arbitrary
	master key version number.
	* configure.in: use WITH_KRB4 for dump support.
	* kdb5_ed_ct.ct: add new dump_v4 command.
	* Makefile.in: link in dumpv4.

I've successfully used this to convert a full database and compared it with
the original by hand -- the only differences were
	1) leading zeros on the new database
	2) k.m date didn't match
	3) mkvno's didn't match (but were consistent)

git-svn-id: svn://anonsvn.mit.edu/krb5/trunk@4663 dc483132-0cff-0310-8789-dd5450dbe970