Use xyann for annotation if attribute available

This change supports the xyann/xyext API change in matplotlib 1.4.0

http://matplotlib.org/api/api_changes.html#changes-in-1-4-x

A conditional is used in this change so it is backward compatible.
Update mpl API dependent code to use LooseVersion
Update lineid_plot version
Merge pull request #4 from sot/mp_1.4.0

Use xyann for annotation if attribute available