Implement core unittests
unittests: Move tests-core into subdirectoy
Merge pull request #961 from authmillenon/core-unittests

unittests: Unittests for core module data strutures
fixed printf specifiers
sys/ping/ping.c: malloc size of type, not size of pointer
native: unify license headers
native/tramp.S: add missing license header
documentation: append my email to my name everywhere
Merge pull request #1143 from jan-schreib/static-code-analyser-cleanup

 sys/ping/ping.c: malloc size of type, not size of pointer
Merge pull request #1184 from LudwigOrtmann/native_license_unification

Native license unification
fixed initializer and Wformat warnings
Merge pull request #1094 from BytesGalore/fix_print_format_warnings_test_vtimer

test:test_vtimer fixed initializer and Wformat warnings
make: print error if make was executed in the root

Fixes #1104, alternative to #1178.
Merge pull request #1183 from Kijewski/issue-1104

make: print error if make was executed in the root
msp430: provide oneway-malloc implicitly

For MSP430 boards oneway-malloc is already used *if* `malloc.h` was
included. The problem is that `malloc.h` is not a standard header, even
though it is common. `stdlib.h` in the right place to look for
`malloc()` and friends.

This change removes this discrepancy. `malloc()` is just named like
that, without the leading underscore. The symbols now are weak, which
means that they won't override library functions if MSP's standard
library will provide these functions at some point. (Unlikely, since
using `malloc()` on tiny systems is less then optimal ...)