net: move ping to sys/net

* moved the former ping module from `sys` to `sys/net/link_layer` and renamed to l2_ping
* use defaulttransceiver instead of cc110x
* some refactoring
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 ...)

Closes #1061 and #863.
Add doxygen comments to MSP's oneway malloc
msp/tests: remove blacklist from test_bloom_bytes

Issue #1061 was fixed.
 make: remove clutter

Remove some outdated example code.
 make: add `BOARD_INSUFFICIENT_RAM` blacklisting

Currently most blacklistings for examples and tests are done because the
board provides too little RAM or ROM. Besides of the actual linking all
the compiling should nevertheless work just fine.

This PR adds the variable `BOARD_INSUFFICIENT_RAM` to tell the
`buildtest` to compile the code for a board, but omit the linking step.
Use `BOARD_INSUFFICIENT_RAM` in examples and tests
documentation: unified descriptive text for boards
copyriot: fixed copyriot header for arm_common
cosmetics: cleaned up arm_common.h

* converted tabs to white spaces, fixed indentation, and removed SVN clutter
documentation: unified descriptive text for cpu
cosmetics: converted tabs into spaces for lpc1768 header
documentation: unified descriptive text for drivers
make: fix clean together with TLSF
net: l2_ping uses radio_packet_t instead of packet_info_t
net: implement L2 ping and pong handler

* also defines L2 payload types
net: renamed handler thread for l2_ping
net: streamlined functions and data types for l2 ping
net: renamed internal variable in l2 ping
net: enabled l2 ping in auto_init

* fixed module dependencies