add lineplot renderer
Added a LocalTime fixtures to use default timezone. Added an option into Graph.Axis.Time to allow fixture to be specified.
Used JavaScript time to find the "days" ceiling.
Fixed date rollup problem.
Made hover to show local time.
Fixed formatDate and formatTime.
add back using our own index iterating through series
add multi renderer to combine different renderers on one graph
add minimal error checking around series renderers in multi renderer
Added instructions on how to run the tests.
Delayed validation in Rickshaw.Graph.Renderer.Multi

While I'm really quite fond of validation and performing it early to ensure that any constraint violations fail fast, unfortunately the check for all the series having a renderer if the graph 'multi' renderer is used cannot be performed in the initialize of the renderer as all graphs will create an instance of the renderer even if it isn't used.  This can be seen by performing:

make clean build

and then npm test
Merge pull request #261 from rojotek/patch-1

Added instructions on how to run the tests.
Merge pull request #262 from rojotek/patch-2

Delayed validation in Rickshaw.Graph.Renderer.Multi
Update README.md
added protection for when no points are available
Handle when there are no points in a dataset
Merge pull request #271 from gregbacchus/master

Fixed bug where no points on the graph causes an error in HoverDetail
Added the ability to specify a specific x value in the Series.addData method(including test).
Set default `magnitude` on `frequentInterval`
When only one item is in the graph, the `_frequentInterval` function
returns an object without a magnitude, and `barWidth` returns
`NaN` as a result.
Update README.md