support for elements as anchors

jQuery is okay with an element object being used as a selector
this patch allows dc.js to work with elements as well as '#id' selectors
artifacts
remove groupOrdering & fix wedge ordering
a work branch
hack for fixing elastic binned bars
Merge branch 'fix-bar-elastic' into work
artifacts
Merge branch 'master' into work

Conflicts:
	dc.js
	dc.min.js
	src/bar-chart.js
	src/base-chart.js
	src/coordinate-grid-chart.js
correct merge of ordering stuff
add dc.utils.isNumber

to complement isFloat and isInteger
use dc.utils.isNumber to end dependence on underscore.js
artifacts
computeOrderedGroups and fix tests

A few pie chart test were relying on errant data
Also, replace orderedGroup with computeOrderedGroups returning array
use computeOrderedGroups for ordinal coordinate grid charts
remove accidental commit of x axis fix

i intended this override to be reviewed separately
use crossfilter quicksort

which in turn will use .valueOf() and is simpler
put summing logic into othersGrouper and do still sort with slices cap

putting summing logic into othersGrouper fixes #209
also it seems more consistent to still sort the wedges if there is a slices cap
rather than just leaving them sorted by value (more stable under changes too)
add tests for slices cap
artifacts
Merge branch 'master' into fix-wedge-sorting

Conflicts:
	dc.min.js