Add support for styling the tutorial popover
What's the issue:
Tutorial popover wasn't getting styling treatment.
What's fixed:
Now it is :-)
Screenshots:
Before:

After:

@oubiwann Hi, thanks for helping! The infobar is already fixed in v2.6.0 release (Haven't push it). However, you can style the TutorialPopover but some color need to be changed.
@oubiwann Can you try this color? Background: #1a2632, btn #243447
I've changed the background color; trying to figure out how to get the tutorial messages back so that I can test the button color ...
Hrm, for the popovers and dropdowns, a caret is used. When the popover/dropdown background color is different from the page background, this caret (or wedge) is visiable; when #1a2632 is used instead, you can't see it :-(
Attaching screenshot:
