Resolves #58. Selections now keeps track of the currently active selection.
Resolves #58. Selections now keeps track of the currently active selection.

VCG/upset,syrenio/upset,XDATA-Year-3/UpSet,syrenio/powerset,zhanghuijun-hello/test,syrenio/upset,XDATA-Year-3/UpSet,VCG/upset,zhanghuijun-hello/test,syrenio/powerset,XDATA-Year-3/UpSet,syrenio/powerset,syrenio/upset,VCG/upset,VCG/upset,zhanghuijun-hello/test,syrenio/powerset,XDATA-Year-3/UpSet,XDATA-Year-3/UpSet,syrenio/upset,zhanghuijun-hello/test