[FIX] Incorrect labels associated in group plots
[FIX] Incorrect labels associated in group plots

A sort was dereferring the appropriate labels and data,
and javascript passes by reference.

Fixes #245

poldracklab/mriqc,oesteban/mriqc,poldracklab/mriqc,oesteban/mriqc,oesteban/mriqc,poldracklab/mriqc,poldracklab/mriqc,oesteban/mriqc