Wt

I am using a lot of Bootstrap Icons.
Usually within a Template and then I am directly adding the Code

Now I thought I could try myself and Upgrade the WIcon class to also support Bootstrap Icons.

This relates to something else I am looking to do, so this is just preparations.

I already implemented it and also updated the documentation within the file.

The Only thing missing:
The Bootstrap Icon font within Wt.
I am adding this in my environment, so it might not be directly accessible for everybody.

And a Test within a JWt environment.

I attached a patch for WIcon.h & .cpp