added NORETURNs to functions that should not return
and added `UNREACHABLE();` to hint the compiler unreachable lines

added right signature for first parameter of `thread_stack_init()`
added `UNREACHABLE();` macro to `cpu/lpc1768/atom.c` and `cpu/msp430-common/cpu.c`
Remove superflous apt-get update from .travis.yml
Add unittests to .travis.yml
Exclude *.c files from make doc
examples/default: add README.md

Fixes #1068
Merge pull request #1071 from LudwigOrtmann/issue_1068

examples/default: add README.md
make/msba2-common: allow TERMPROG override
Merge pull request #1141 from LudwigOrtmann/msba2-term

make/msba2-common: allow TERMPROG override
fix buildtest with oonf_api

Don't try to checkout oonf_api if it's already present
net/ip: apply workaround to fix IP forwarding

When sending a packet a workaround is applied when ndp_get_ll_address() returns NULL as is's not implemented properly yet.
The same should happen when a packet is forwarded as it's dropped otherwise.
net/ip: fix wrong double negative in the comments
Merge pull request #1046 from benpicco/fix_routing

fix forwarding packets when ndp_get_ll_address() returns NULL
Merge pull request #1142 from benpicco/fix_oonf_build

fix buildtest with oonf_api
Exterminate old-style function definitions
Exterminate old-style function declaration/prototypes
make: add own file for CFLAGS feature tests
make: fast out on old-style function definitions
sys:crypto: put ciphers into one module
Add process indicator to compile_test.py
Fix documentation for lifo.h