busy_indicator
==============
A javascript library for displaying a busy indicator.
Using
=====
Example:
var busyi = new busy_indicator(document.getElementById("busybox"),
document.querySelector("#busybox div"));
busyi.show();
setTimeout(function () { busyi.hide();}, 10000);
The constructor can also accepts a show callback and a hide callback, which
are called on show() and hide() actions.
show() can be called many times - only the first call performs show actions and
executes a show callback, subsequent calls only increase internal counter. In
this case, hide() must be called an equal number of times - only the last call
performs hide actions and executes a hide callback.
Examples - ex*.html.