This changes makes it possible to store custom settings
in individual files inside the directory /etc/sysctl.d/.

Signed-off-by: Stefan Tomanek <stefan.tomanek+openwrt@wertarbyte.de>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@46239 3c298f89-4303-0410-b956-a3cf2f4a3e73