group containing axis marks should have enter propertyset, not only update.
barley example should use enter for when marks are initially processed (was only update)
use type provided by scale's constructor, if any
update built files
Merge pull request #81 from malecki/axis-enter

enter property set for axis group element
Expose extensible scale lookup.
Fix exit update bug (issue #82).
Fix svg empty mark bug (issue #60).
Clean up canvas renderer, and stroke hit tests.
Update stocks example x-scale.
Improve support for x2, y2 properties (#63).
Disable interpolation for text labels.
Refactor bounds calculation. Improve legend sizing and layout.
Add auto-padding calculation.
Improve security for property parsing.
Add grouped bar and iris scatter examples.
Parallel coordinates and choropleth examples. Update to latest D3.
Add TopoJSON support.
Update examples.
Cull redundant compilation of axes and legends.