minix/lib/libarchive

What's supported, what's not
----------------------------
This port corresponds to libarchive-2.8.3. The following formats supported
by libarchive are NOT supported in the port:
1) iso9660
2) various variants of cpio

In addition though xz and lzma are included, due to the lack of
liblzma and xz utilities on Minix they are of not much use. Of the remaining
formats I know that tar and its variants (tar.gz, tar.bz2 etc) work. 

Notes on the port
-----------------
The cause for all changes is the fact that ACK does not have a 64 bit types.
Most of the changes are 'downsizing' of types from 64 bits to 32 bits.
Also a signed type is used for the measuring sizes so nothing > 2GB will work.

Most of the changes are repetitive and can be classified into two types:

1) Changing sizes/offsets/timestamps from 64bit types to size_t, ssize_t, off_t
   time_t
2) Changing functions that either decode or encode sizes/offsets/timestamps
   from or to archives to use 32 bit types.