Until now, the LGPL license of these files (that are imported from Gnulib)
was missed in the 'debian/copyright' file.

With this commit, it has been added, along with a comment on the purpose of
these files.

This issue was reported by Thosten Alteholz.

After the previous commit, I thought its necessary to change the Debian
version to 0.12-2, but Ole just reminded me that that was not necessary, so
I am correcting it here.

In the previous commit, I forgot to update the date of the entry which is
corrected here.

Ole Streicher recommended to use the old email entry (on alioth.debian.org)
to help in linking Debian Astro packages together and to ignore the micro
version of the standards (so only three digits are included).