add grunt, see more in README.md about how to use intstall and use grunt
FIxing bug in line.js.
Merge branch 'master' of https://github.com/novus/nvd3

Conflicts:
	nv.d3.min.js
Adding historical bar chart code.
ran make on nv.d3.js
Merge branch 'grunt' of https://github.com/lihongxun945/nvd3 into lihongxun945-grunt

Conflicts:
	nv.d3.min.js
fixed a merge conflict. No change to master code, so this commit is not tagged
Merge branch 'master' of https://github.com/novus/nvd3

Conflicts:
	examples/historicalBarChart.html
	nv.d3.js
	nv.d3.min.js
	src/models/historicalBarChart.js
	src/nv.d3.css
Adding PNG image to show what a sample line chart looks like. For the WIKI documentation.
updated multiChart to allow changing yDomain on yscales
Merge branch 'master' into development

Conflicts:
	nv.d3.js
Merge branch 'development' of https://github.com/novus/nvd3 into development

Conflicts:
	nv.d3.min.js