Enable seamless compression for WIN32

In the archival code we pretend that WIN32 is a no-MMU platform and
use the new mingw_popen_fd routine to pipe data to/from commands
to compress/decompress.

The pretence is maintained by redefining MMU macros in bb_archive.h.
This is mostly used in the archival code but there are a handful
of places where it's used to access public interfaces.  The symbol
BB_ARCHIVE_PUBLIC is defined in these places.

With these changes:

   tar supports seamless compression/decompression
   rpm2cpio and dpkg-deb can be enabled

1 files changed, 0 insertions, 1 deletions

diff --git a/README.md b/README.md
index d4140487c..90a89521a 100644
--- a/README.md
+++ b/README.md
@@ -16,6 +16,5 @@ Then just `make`.
 
  - Use forward slashes in paths:  Windows doesn't mind and the shell will be happier.
  - Don't do wild things with Windows drive or UNC notation.
- - tar doesn't support seamless compression/decompression:  use a pipeline to a compressor/decompressor.
  - Wildcard expansion is disabled by default, though it can be turned on at compile time.  This only affects command line arguments to the binary:  the BusyBox shell has full support for wildcards.
  - Handling of users, groups and permissions is totally bogus.  The system only admits to knowing about the current user and always returns the same hardcoded uid, gid and permission values.