configfile.c: Include more than one files in lexicographical order.

configfile.c: Include more than one files in lexicographical order.

Using qsort() and strcmp() the list of files (after reading the contents
of a directory or expanding globs) is sorted before inclusion. As the
order of options in the config file matters this is more convenient.

Signed-off-by: Sebastian Harl <sh@tokkee.org>
Signed-off-by: Florian Forster <octo@huhu.verplant.org>