Merge from vendor branch tnftp:

Merge from vendor branch tnftp:
Import tnftp 20050103.
Various changes, including:
	* forbid mget of filenames that aren't in or below the local cwd.
	* improve auto-fetch transfers
	* improve www/proxy authentication support
	* improve http response header parsing
	* change UCB-licensed code from 4-clause to 3-clause