UID Mapping

	Added UID mapping to filePro, ddir/dprodir option F5.
	This allows for UIDs (User IDs) to be aliased to specific 
	usernames. In the event that a login account is removed from 
	your system, this can be used to maintain the link between the 
	removed login's UID and those stored in filePro, effectively 
	allowing system variables such as @CB and @UB to be mainained.

	Windows Only:
		This also has the added benefit of allowing @CB and @UB to 
		function on Windows by linking a "pseudo" UID to a given 
		username. These UIDs are automatically generated but can 
		also be manually added. When a user opens filePro and their
		username does not exist in the UID map file, a UID will 
		be generated for that user. filePro will find the next 
		available UID in the list, starting from 2000, and assign 
		it to that username.

		On all platforms, UIDs stored in this program must be unique 
		and in the range 0-65535. Usernames can be duplicated on Unix 
		and Linux platforms, but must be unique on Windows.

		Usernames are case-sensitive on Unix and Linux platforms and 
		are case-insensitive on Windows platforms.

		Environmental Variables:
		PFUIDMAP = /path
		Alternate filePro UID map file. (Use full path)
			Note: Must be set in the environment.

		PFUSEUIDMAP = ON 
		Allows filePro to do UID mapping. Also expands the maximum 
		username length returned by @CB, @UB, and @ID to 32.
		Default: ON