BTT: Added user guide

BTT: Added user guide

o  Added in new btt/doc directory w/ Makefile.
o  Added in btt/doc/btt.tex: First pass at a User Guide for btt.
o  Fixed usage for btt (missing -A in the usage).
o  Bumped version of btt to reflect this document.
o  Cleaned up a leftover debug entry

Note: The document does /not/ have the charts intended in the final
copy yet. Hasn't even gone through a spelling & grammar & consistency
check yet.

But it's a start...

Signed-off-by: Alan D. Brunelle <Alan.Brunelle@hp.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>