SVG Sprite icons

[Sam]

SVG Sprite icons use a HTML snippet like this:

<svg class="icon icon-admin"><use href="/assets/e49e1d21/symbol-defs.svg#icon-admin"></use></svg>

This could be implemented with the following changes:

1. Add iconTag, with default <i>. This allows us to change it (developers might use different tags for things like font-awesome, <span> for example).
2. Allow HTML in iconText.

Configuration would then be:

{
    icon: 'icon icon-admin',
    iconText: '<use href="/assets/e49e1d21/symbol-defs.svg#icon-admin">',
    iconTag: 'svg'
}

It would be even cleaner (from a configuration perspective) if we add support for some simple string replacements:

{
    icon: 'icon icon-admin',
    iconUrl: "/assets/e49e1d21/symbol-defs.svg",
    iconText: '<use href="{iconUrl}#icon-admin">',
    iconTag: 'svg'
}

But this makes the code more complex..

[Marcelo Dolza]

Hi @SamMousa , could you make a PR? thanks