update to dojo 1.8
fix some dojo 1.8 style issues
recalibrate vertical ruler drawing for 1.8 dojox charting
update release notes
Fixed a bug in which the Y-axis scale for feature density histograms was sometimes drawn incorrectly.
tweak styling of feature histograms
some more fixes to ruler drawing
tweak feature hist display a little
Merge branch 'master' into dojo_18

Conflicts:
	track_styles.css
tweak CSS for nav box to look better with dijit 1.8
Merge branch 'master' into dojo_18