Updated this to not contain usage information, which has been
moved to the dev-manual. I diff'ed out this commit and there
are some changes that resulted from accidental deletion and
restoration of a large amount of text.
(From yocto-docs rev: fdefcfd77811d2cfe65d51b70f3bc69018f3de81)
Signed-off-by: Scott Rifenbark <scott.m.rifenbark@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>