New UBL 2.0 schedule

Hello UBL TC,

As stated earlier, I'm in the process of separating our
deliverables for 2.0 into "normative" pieces and "informative"
pieces.  Here's the first output of that effort: a new schedule
for the normative pieces.  I've already reviewed the basic
milestones in this week's Pacific and Atlantic TC calls, so there
should be few surprises.

Note that this schedule may need adjustment when I start trying to
map out a timeline for the informative parts of the spec.

Jon