moving tooltips to base class
moving tooltips to base class

ChakriCherukuri/bqplot,bloomberg/bqplot,dmadeka/bqplot,SylvainCorlay/bqplot,ssunkara1/bqplot,ssunkara1/bqplot,ChakriCherukuri/bqplot,bloomberg/bqplot,bloomberg/bqplot,SylvainCorlay/bqplot,ChakriCherukuri/bqplot,rmenegaux/bqplot,dmadeka/bqplot,SylvainCorlay/bqplot,rmenegaux/bqplot