xfce4-calculator-plugin: Ambiguous license header

[Akbarkhon Variskhanov]

Hi all.

During the process of packaging `xfce4-calculator-plugin` for Debian,
we noticed that the license headers for source files in panel-plugins
are ambiguous. Here is one as an example:
>  This program is free software; you can redistribute it and/or modify
> *  it under the terms of the GNU General Public License as published by
> *  the Free Software Foundation; either version 2 of the License, or
> *  (at your option) any later version.
> *
> *  This program is distributed in the hope that it will be useful,
> *  but WITHOUT ANY WARRANTY; without even the implied warranty of
> *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> *  GNU Library General Public License for more details.
> *
> *  You should have received a copy of the GNU General Public License
> *  along with this program; if not, write to the Free Software
> *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
> *  USA.

First and last paragraph hint that it's packaged under GPL, while the
middle one refers to LGPL. AFAIK, GNU doesn't allow mixing license
notices.

Moreover, there is COPYING.LIB in the source tree as a result of this.
It's not obvious whether the files are licensed under GPL or LPGL.

Was it a copy-and-paste mistake initially or am I missing something
here? Which one am I supposed to choose? Should I include both in the
binary package? Please clarify the situation.

Regards,
Akbar.