Change from UIP_CONF_IPV6_LOADNG to WITH_IPV6_LOADNG
Add readme file for loadng
Compile both RPL and LOADNG. The trick is that depending on the macros RPL_ROUTING_PROTOCOL and LOADNG_ROUTING_PROTOCOL defined in rpl.h and loadng.h, the state variable has not the same type in uip-ds6-route.h. So some includes had to be shuffled a bit so that uip-ds6-route.h is included after rpl|loadng.h
Removes macro definition, they belong to the example Makefile, where the user can choose between loadng or rpl.