start of work to add ordinal and time scales to x axis
fix for marker height
Fixes to ordinal x axis

- uses rangePoints to handle scatter graphs, will need to resolve this when we try to do either bar or scatter.  For y too.
- fixed range order of extent so it doesn't reverse entries
Time axes and markers
Merge branch 'upstream/master'

Conflicts resolved:
	js/widget-callouts.js