basic RAR single-file decompression working

However, getting unrar to build as part of the be build system could be a
significant challenge.

After that's taken care of it should be simple to link up the decompression
into the scanner.

Then there are significant opportunities for cleanup of the JHU code.
start of work to remove unneeded parts of unrar

to simplify cleanup of unrar code, as much as possible is being removed.  Work
started today with fruitless simple makefile modifications, and now is
continuing with gprof
Removed crypto from unrar
removed sha1 dependency from unrar + streamlined testing
deleted files no longer depended on
removed dependency on list
removed find and scantree dependencies
removed recvol dependency
removed filcreat dependency
removed rarvm dependency
removed consio and log dependencies
removed ulinks dependency
removed os-specific unpacking dependencies
removed split volume dependency
removed isnt dependency
removed dll dependency
prevent extraction of multiple components
copy unrar code into be rar folder
rar module added to build system
warning cleanup in array.hpp