shell: print command if not found
shell: fixup test_shell expect scripts
shell: fix newlines
x86: add read-before-write check at runtime

Finding read-before-writes statically is quite difficult. In native we
can use valgrind, but on boards without an MMU we are out of luck.

x86 has an MMU, let's use it.

If `-DDEBUG_READ_BEFORE_WRITE` was set, then pages on the heap get
initialized upon first use. If the page was read before written, then a
debug message with the virtual and physical address of the memory
location is printed, as well as the address of the offending instruction.
you can never have enough debugging in RPL
some minor fixes and debugging
set correct transceiver stack size for debugging
fixed debugging for cc110x
net: IPv6: RPL: more debug output
rpl: debug: use DEBUGF where necessary
drivers: added rgbled driver
Merge pull request #891 from OlegHahm/rpl_debug

net: some debug code
Merge pull request #1105 from Kijewski/shell-print-not-found

shell: print command if not found
Merge pull request #1257 from Kijewski/shell-fix-newline

shell: fix newlines
Merge pull request #1259 from Kijewski/x86-heap-check

x86: add read-before-write check at runtime
Merge pull request #1316 from haukepetersen/add_driver_rgbled

drivers: added rgbled driver
Refactored crypto module into structured directoy layout

* crypto ciphers now located in sys/crypto/chipers/*
* crypto hashes now located in sys/crypto/hashes/*
Added block cipher mode operation support

The following cipher modes are now supported
* Electronic code book (ECB)
* Cipher block chaining (CBC)
* Counter (CTR)
* Counter with CBC-MAC (CCM)
Fix undefined references issues for pow

Linker (for gcc < 4.9) is complaining about missing math functions
(like pow) even though we have -lm in "Makefile.include". If we put
"-lm" as last statement it just works.
Added unittests for crypto aes operations