Compute axis bounds datawc_x1, _x2, _y1, _y2 for vector plots.
Also, added a comment about how these could be done better.
Supply title and source to the contour part of plot set 6.
They can be omitted now from the vector part, but seem to be doing no harm there.
Merge branch 'devel' of github.com:UV-CDAT/uvcmetrics into devel