[BS4] Carousel not working well in IE11.

Created by: pappabj0rn

I'm seeing several issues with the carousel in IE11.

• Transitions don't really work
• Indicators are a bit of to the right
• During transition, captions from both current and next slide are showing

Tested on Win 7, 8.1 and 10 with IE11.

Issues are live on https://v4-alpha.getbootstrap.com/components/carousel/#with-captions