resize must return _chart
Merge branch 'apply-config' of https://github.com/krikrou/dc.js into k
modify getClipPathId: root() instead of anchor()
modifify getClipPath
[#116] handle negative values in bar chart
[#116] improve y min/max value handling
improve negative value handling in stackable chart
[#116] implement negative elastic Y handling
[#116] improve bar chart test cases for handling negative values
[#116] improve bar chart handling of mixed positive and negative values
[#116] improve line chart handling of mixed positive and negative values
[#116] implement line chart handling of mixed positive and negative values with stacking
Extract method refactor of onClick

The implementation of the two portions of the `if` statement were the
same.  This pulls that into a common function that can be used directly
to in case someone needs to programmatically set the filter values.

Note, `onClick` did not have any direct tests, so I wasn't sure how I
should proceed with that.  All current tests still pass, so assuming
they have adequate indirect coverage of `onClick`, this should be ok.
added global expireCache
Merge branch 'master' of https://github.com/NickQiZhu/dc.js
merge with origin master
improve onClick test coverage
Merge pull request #122 from tswicegood/extract-onClick-implementation

Extract method refactor of onClick
Merge branch 'master' of github.com:NickQiZhu/dc.js
improve onClick test coverage