Redraw vectors on 'viewreset' (fixes #19)
Center vectors over data point
Merge pull request #21 from enthought/bug/rescale-on-zoom

Redraw vectors on 'viewreset' (fixes #19)
Merge pull request #22 from enthought/enh/center-vectors

Center vectors over data point
Merge branch 'master' into enh/barb-location

Conflicts:
	frontend/js/vector.js