sqm-scripts & luci-app-sqm: experimental QoS

sqm-scripts is a new QoS system from Cerowrt / Bufferbloat.
I have tested it in my own community build.

This pull request contains both the sqm-scripts itself and also the Luci GUI to manage it. 
Both packages are added to /net

More info at:
http://www.bufferbloat.net/projects/cerowrt/wiki/Smart_Queue_Management
http://www.bufferbloat.net/projects/cerowrt/wiki/Setting_up_SQM_for_CeroWrt_310

Dave Täht submitted this first via openwrt-devel mailing list in March 2014,
but that was not picked up before the switch to Github:
http://patchwork.openwrt.org/patch/5078/

I have modified:
- set the default interface to be eth1, like the typical Openwrt default.
- modified config to hide some of the advanced options by default
- beautified Makefile & menu items a bit
- added Toke Høiland-Jørgensen <toke@toke.dk> as the maintainer, as discussed
  in https://github.com/dtaht/ceropackages-3.10/issues/8#issuecomment-59215905

Signed-off-by: Hannu Nyman <hannu.nyman@iki.fi>