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
update version number
start v1.6 dev
Merge pull request #1 from NickQiZhu/master

Pull latests
Fix for ordinal barchart not rendering when first two bars are empty
remove global functions
remove old pie chart labels upon update
fix overzealous jshint cleanup
rebuild with #254
set tests failing for #248 to pending so build will succeed
build for node versions .8, .10, .11 with travis-ci
fix bug null/undefined bug
Merge pull request #263 from NickQiZhu/fix-node-8

fix bug null/undefined bug
set version to 1.6.0-dev