QuickUpload should show some info about the upload

[alfonsoml]

When the user presses the Upload button, there's no indicator that something is happening.

Reusing the dialog's throbber seems like an easy solution.

[alfonsoml]

Proposed SVN patch

[alfonsoml]

The change is basically allowing the throbber parent to remain in the DOM and then calling it from the dialogs as needed.

[martinkou]

There are two problems with the current implementation:

1. If the user tries to upload two or more files via the upload tab, then the throbber bar would get longer with each upload. This is actually my fault, though. It happens because the Throbber object in fckdialog.html is designed to show the throbber once only (note that throbber bar is added by DOMNode.appendChild() in the Show() function).
2. While the throbber is being shown on the dialog, the "OK" button and the tabs should be disabled.

[alfonsoml]

Revised patch

[alfonsoml]

I've addressed both issues in the new patch.

[alfonsoml]

Fixed with [2043]