Balloon panel support attach without showing the toolbar

[wojtekw92]

Are you reporting a feature request or a bug?

Feature request

Provide detailed reproduction steps (if any)

Balloon panel should have option to attach panel without running show function.

We should change attach method to accept options instead of focusElement as a second param.

options object should be like this:

{
    focusElement: CKEDITOR.dom.element/Boolean
    show: Boolean
}