Tooltips with scrolled div (not only body)

Tooltips with scrolled div (not only body)

This is a fix for the Issue: [https://github.com/Regaddi/Chart.js/issues/27][https://github.com/Regaddi/Chart.js/issues/27]
Update Chart.js

Restores original variable names ("element" to "e")
Update Chart.js

delete enter
Merge pull request #28 from DavidBM/patch-1

Tooltips with scrolled div (not only body)