auto blur button on click, btn-default disabled and focus shows spinn…

[lookbadgers]

…er white on white background, blur allows background to change colour and spinner to appear as white on grey

[lookbadgers]

If a button has btn-default the spinners does not show up if the spinner is triggered on click. The spinner shows as white on white.

This fix means when ever a spinner starts, the button is blurred. Therefore avoiding the spinner not showing up for btn-default.

The alternative solution would be to manually call blur() before every ladda('start'). If a button is disabled it does not make sense for it to have focus, therefore it seems better that ladda manages this as well.

        <button type="button" class="btn btn-default ladda-button" data-style="zoom-in">
            <span class="ladda-label">
                <span class="glyphicon glyphicon-pencil"></span>
            </span>
        </button>

[terales]

Problem reproduced in JSFiddle: https://jsfiddle.net/terales/5v2v0mgL/1/

But I don't see how proposed fix helps, see JSFiddle with ladda.js from lookbadgers/ladda-bootstrap: https://jsfiddle.net/terales/5v2v0mgL/2/

@lookbadgers can you update JSFiddle to reproduce a solution, please?

[terales]

@msurguy I think this PR could be closed in favor of #65 (comment): use data-spinner-color attribute to change color of btn-default

[msurguy]

@terales thanks! That makes it easy to find if somebody's looking!