Custom Buttons

[chad-autry]

I would like a feature to allow for custom buttons + callbacks. In fact I've developed the bulk of the feature, but don't have the personal time to polish it sufficiently for a pull request.

master...chad-autry:master

Issues with my current changes:

1. Did not fix/add tests. Disabled tests
2. Does not show only on-hover like other buttons (and in fact I disabled that for the CopyButton on the branch due to my own desires)
3. dev-server examples could use distinct icons
4. Styling re-uses from CopyButton, no distinct default style/color. No way to pass in style parameters or button color
5. README.md needs to document the new parameter

[idonava]

I'm glad I found this issue.
I think Custom Buttons support is required and I'll definitely use this feature.

If you need a hand let me know...

[tslater]

@chad-autry This is awesome. I'll have to try your fork! Do you have a quick example of how to make a custom button?

[ihor]

@chad-autry awesome work! Do you plan to submit a PR?

[chad-autry]

I am unlikely to find the time to make a PR myself, the five issues noted in the original comment need to be taken care of before it could be merged.