native profiling tools support

examples/hello-world: return instead of busy loop.

make: Add DEFAULT_MODULE and DISABLE_MODULE

core: Remove duplicate function definition in queue.h

rpl: Fix RPL app for clang

Closes #926

Make: Add include paths automatically for USEMODULES

make: replace MAKEBASE with RIOTBASE

Fix for CC2420 radio driver for TelosB

closes https://github.com/RIOT-OS/RIOT/issues/959

Make neighbor cache remove function public

msp430: hwtimer: handle overflow correctly

Initial import of low-level PWM driver interface

Update README.md

ccnl: remove dead code

Application developers use `$(USEMODULES)` in their Makefiles to have
the relevant functionally automagically added to their apps. This even
does basic dependency tracking by means of `Makefile.dep`.

But an important thing is missing: the automatic adding of include
paths. This is inconvenient, error prone, and will hinder the RIOT core
developers in future to change folder structures.

net: transceiver: fix ignore command

remove empty else clause

tests/pkg: fixed issues from #919

- added UNDEFINED device for compatability
- adjusted meaning of return values for init and set functions
- overdue spell fix

Initial import of low-level GPIO driver interface