The Book Industry Standards and Communications (BISAC) Group is a US body that
among other things, has defined a set of plain text data formats for electronic
data exchange within the book industry. These formats are now deprecated, but
are still in use in some place (including segments of the Australian market).

This set of classes are just convenience wrappers around some of those formats,
designed to make reading and writing them just a little less painful.

At this stage I've implemented support for 3 message types. See their classes for
specific documentation.

- Bisac::Message - Title metadata message
- Bisac::PO      - Purchase Order
- Bisac::POA     - Purchase Order Acknowledgement

I make no claims about this being a polished library, it's just a quick hack I
needed so I could extract the data and store it somewhere more useful.

I presume the BISAC specs are copyright to someone that isn't me, and I'm not
claiming otherwise.

= Links

- Project source: http://github.com/yob/bisac/tree/master
- Standards body: http://www.bisg.org/bisac/
- Partial specs:  http://www.anchordistributors.com/EDIInfo.aspx