Tooltips in sparkline view

[pl-ki]

Would be very useful with tooltips over the attribute band (could also extend down over spark line graphs) to see the full attribute names in a dense plot, like here:

http://loom.linnarssonlab.org:8123/dataset/sparklines/Other/L5_All.agg.loom/NrBEoXQGmAGHgEYq2kqi3IExagZjwBYI0R5sA2KIlDO7eRWeYbRa~VGdgdjtTQuKIRlIxwZALSwAdEWy92AVmW9KiXogAcvZSlksisIvjUBOZomWVsy6FRpR9tHWlbpu6TDBx5CvjTiIHDOTkwMTCwwtFxo~ALiwtxMwYjm8Am0wMrm~D7ImBBAA