added support for text-based toolbar options

[mikeangstadt]

Added the ability to pass innerHTML text for toolbar icon anchors.

[WesCossick]

Can you submit a JSFiddle that demonstrates this change? That way, it can be tested by myself and other contributors.

[mikeangstadt]

I'm using it as a node dependency, so I don't have my code hosted anywhere to point at from a JSFiddle - BUT! Here is a configuration overriding the Preview button in the toolbar that you can use in testing it.

https://jsfiddle.net/vx1qjgvo/

[sparksuite-bot]

A JSFiddle for this pull request can be found here. If it doesn't inherently demonstrate the proposed change, please fork the fiddle and make the necessary modifications to demonstrate this pull request. Then comment the new URL to your forked fiddle.

[charleneChen]

A new demonstrated JSFiddle can be found here

https://jsfiddle.net/07f4ryhj/

[riccardoratta]

This feature is fundamental for use others icons packs like material icons! Indeed we have to write the InnerHTML proprieties to get the<a class="material-icons">face</a> button.

Please @WesCossick, can you merge the branch?

[guifeliper]

@WesCossick can you merge this branch?