11 June 2002:
	I ripped out old code for walking through the DTDB and used MoreFiles instead.
	I now call Launch Services if we're built for Carbon and it's available.
	Launch Services is your friend!
	Note that I continue to use FSSpec's, not FSRef's, for the call results 
	because I attempted to maintain compatibility with existing clients.
19 June 1991:
	I'm now NILing the ioNamePtr field of the param block before calling PBGetVolParms, which
	should prevent some unsightly crashes.
17 June 1991:
	Got it to work properly with file servers. NOTE: You may still have trouble with particular
	applications on particular file servers, because a lot of servers seem to have screwed-up
	desktop databases that don't have entries for various apps on the server. This is the
	server's fault, not mine or PBDTGetAPPL's!
7 June 1991:
	Added the ability to find an application on disk without launching it.
	Changed the boolean allowLaunch flag to a more general mode setting to allow this.
	Renamed the whole thing to SignatureToApp.
	Made the process parameter optional.
	fnfErr, not afpItemNotFound, is returned if no application is found on disk.
	Extended the 'Launch' tool to try out all three modes.
	Rewrote a lot of this documentation.
