fixes #5695

cpu/native: fix thread_stack_init

The pointer arithmetic for the calculation of the context storage was off
due to the change of the stack's pointer type from unsigned int to char.
Fix offset calculation by not adjusting for unsigned int width anymore.

cpu/native: rewrite cpu_print_last_instruction

In case NDEBUG is not defined, `crash_code` is used later on

circumvent assembly by using a GCC/LLVM builtin

cpu/cc2538: fix debug statements

gnrc: provide my master thesis in documentation

Adapt Si70xx temperature/humidity sensor for SAUL

make: BUILDRELPATH without call to git

Adjust find-tty.sh to return all matches, then use it in boards/cc2538dk

cpu/msp430: initialize gpio as input OR output

cortexm: Hard fault: Try to output as much as possible even with corrupt stack

drivers/bmp180: add dependency to periph_i2c

tests: driver_bh1750: fix application name

make: allow "pseudo-packages"

core: clist: clist_lpeek(): add missing return statement

drivers: l3g4200d: fix saul doxygen group

base64: Use stddef.h for size_t

tests: moved printf_float test to unittests [adopted]

this test is covered by the unittests and not longer needed

core: improve clist

core: mbox: initial commit