convert into host byte order in UDP reception
udp_packet_handler uses printf, stack must be bigger
fix copy&paste typo
moved stack from header to C file
another NTOHS was missing...
set received parent lifetime when creating a new parent
initializes RPL instances
printf is used in sixlowpan mac layer, stack needs to be adjusted
use local packet_length variable in sendto

Having a global packet_length variable doesn't seem to be the best
idea. To avoid trouble, a scope local variable should be preferred.
remove vtimer object before (re)scheduling it
check if preferred parent was set before comparing
Merge pull request #384 from OlegHahm/sixlowpan_fixes

printf is used in sixlowpan mac layer, stack needs to be adjusted
enforce KERNEL_CONF_STACKSIZE_PRINTF in kernel.h
Merge pull request #397 from thomaseichinger/kernel_conf_stacksize_printf

enforce KERNEL_CONF_STACKSIZE_PRINTF in kernel.h
Merge pull request #383 from OlegHahm/rpl_fixes

Small RPL fixes
Merge pull request #347 from OlegHahm/destiny_fixes

UDP reception, stack sizes and typos
change my email address

kaspar.schleiser@fu-berlin.de will be obsoleted soon. Replace it with
kaspar@schleiser.de, which will (hopefully) stay.