fixed unzip

[Bill Turner]

The only problem with both the original Unzip posting and this was that they
were written for byte-swapping architectures.  If you want to have it work
on non-byte-swapping systems, apply the following changes:

1) All of the signature values need to be byte-swapped.  I.e.,

	local_file_header_signature is 0x504b0304L
	central_file_header_signature is 0x504b0102L
	end_central_dir_signature is 0x504b0506L

2) In the routine get_byte, declare nibble as unsigned char rather than
   unsigned int.

----Bill Turner 
HP Corvallis Workstation Operation