	IEMappedFile is a public domain class.  It is designed as a central resource to map files into memory and make sure that only one object corresponds to one filename.  It encapsulates the following information:
	-the filename (which has been NXUniqueString'ed)
	-the open file descriptor
	-the pointer to the memory which is mapped to the file
	-the size of the file
	-the last modify time of the file
	
	The factory object keeps a HashTable of filenames and objects to insure that only one instance is created for a given filename.  	There are two methods which return the pointer to the memory map.  The -data method just returns the pointer.  The -dataUpdated method first checks to see if the file has been modified, and if it has it remaps the file and returns the data pointer.
	This is a read only object and does not support writing memory to disk, or even writing to memory.
	Please send me all bugs found and/or corrected!  I have used it but not extensively, specifically the archiving support.
