Encrypted Archive Support - new in v1.30

Thanks to Mike Wilkey <mtw@allways.net> for his very useful source
code and helpful comments.  He basically got this functionality
working by himself.  I just plugged in his result to TZipMaster.

The source for the actual encryption algorithm is the overseas link
pointed-to by InfoZip.  I have learned that this is NOT being controlled
by the US government, so I am including it with this release.

Specifically, I used the crypt.c and crypt.h files from this version
of the InfoZip code:  ZCRYPT27.ZIP

I added a few lines of code to assist in debugging, but the
bulk of the code is unchanged.

