Introduce package for additional experimental scripts for sqm-scripts.
The target is to provide an opportunity to test QoS scripts and qdiscs
still under development. E.g. cake related scripts can be placed here
for testing.

sqm-scripts and luci-app-sqm will pick up the new scripts automatically.

Initially the package contains five cake-related scripts.

The package depends on the main sqm-scripts package.

Signed-off-by: Hannu Nyman <hannu.nyman@iki.fi>