update to contiki 2.6
update to new contiki

also reenable the deprecated clock_delay function, since we need it. for
now.
update usb stick, too
remove mDNS resonder

it hasn't been doing anything except littering the network with useless
packet since our switch to site-local multicast
deduplicate provisioning app
deduplicate button handling code
really deduplicate button handling code
disable RPL routing on sockets for now
remove mdns_responder from makefile
remove statemachine upload code from webserver
remove forwarding flag getting/setting code
more button generalization

next step: hexapush
rebuild hexapush on top of the common button app
Merge branch 'bs-contiki-merge' into development

Conflicts:
	firmware/Hexabus-Socket/Makefile