v1.3.0

Changes in Version 1.3.0

o Typos in the berkeley dataset reported as issue #7 are fixed.

o The argument keep.data is added to sitar with default TRUE. This saves a
copy of the data in the object, which avoids some environment issues.

o ob_convertr is rewritten and extended with the addition of ob_convertr2, and
is now much faster. As a result the interface is altered - a breaking change.

o The dataset deren example is updated to match the revised ob_convertr.