Wiki emoji and icon support

To all wiki editors.

The wiki now supports emoji.

It requires the setting of the :stylesheet: attribute in your document header. This is explained in the linked document above.

In the future, I would like to remove this requirement but I do not know the Ruby language so until I know it better (no intention of learning it really) or someone who does know it helps fix this issue,

we will have to just add the stylesheet attribute to the header.

Edit: Added info for using font awesome in pages.