sm: Move qualified.txt from datadir into sysconfdir

* doc/Makefile.am: Move qualified.txt into examples.
* doc/qualified.txt: Move into examples, remove trailing spaces.
* doc/examples/README: Document qualified.txt.
* doc/gpgsm.texi: Move qualified.txt from datadir into sysconfdir.
* sm/qualified.c (read_list): Move qualified.txt from datadir into
sysconfdir.

The qualified.txt is maintained by Administrator it is a configuration
file. In the past it was a hybrid, provided by package and controlled
by the Administrator, however, it is no longer maintained by package.

• Signed-off-by: Alon Bar-Lev <alon.barlev@gmail.com>