ENH: Update qMRMLChartView to expose jqplot marker size and line width options

Exposes two new options from jqplot:

• 'size' allows to select the size of the marker
• 'lineWidth' allows to select the width of a line.

This allows to change these options when using qMRMLChartView. Both
properties should be set with a string containing an integer (greater
than 0).

From: Francois Budin <francois.budin@kitware.com>

git-svn-id: http://svn.slicer.org/Slicer4/trunk@24968 3bd1e089-480b-0410-8dfb-8563597acbee