Added option to specify which column a series should use as x-column
Merge branch 'master' into dev-irregular-data
Reworked reading of series. Now with possibility to read from any column index.
Changed so that all configured options in seriesMapping is imported as properties on point objects
Test exports should be commented out
Merge branch 'master' into dev-irregular-data
Need to be able to switch 'x' reader to 'name' when axis is categorical
Added test
jslint fixes
Merge branch 'master' into dev-irregular-data
Merge branch 'master' into dev-irregular-data
Updated wrong paths in heatmap demos
Fixed #2928 causing the halo to be misplaced on multiple pane positions and inverted line charts.
fixed z index issue on columns

Closes #2936
Fixed #2930 causing all gauges not to update in Highcharts 4.0.
Updated map parser study
Fixed #2939 causing wrong clipping of 3D charts rendered with highstock.js.
Fixed #2940 causing gradient colors not to apply on strokes in Highcharts 4.
Merge branch 'master' into dev-irregular-data
Fixed bug causing columns to be z-sorted in the wrong direction.

Closes #2941