test1
Added features for allowing multiple series and selecting markers.

## Update in 0.9.2

* Now supports a different way of passing the inputs. See README.md for
details.
* Supports more than one data series per chart
In the case of bar chart, the values will be stacked according to data
sequence.
* Supports the selection of marker characters
User can specify one marker, in which case all line sequences will use
that marker. Or user can specify marker at least the same number as the
number of data series.
* Now allows nil in the y-values, in which case the corresponding point
will be left blank