Before we are able to do a proper exchange of pairing parameters,
we need a unified way of building pairing requests and responses.

For IO Capability we use the value that was set by userspace,
using the management interface.
Signed-off-by: NVinicius Costa Gomes <vinicius.gomes@openbossa.org>
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>