Refactor and add multiply by word size to get the usage in number of
bytes instead of in number of words.
Verified implementation by manual memory inspection in GDB.
- removed coretx-m[0|3|4]
- moved their content to cortexm_common
- adjusted cortex Makefiles to this new name
- adjusted cortex Makefiles new structure
- fixes to cortexm-common
- Added ARM CMSIS headers to cortexm_common
- thread_exit fixes to cortexm-common
- cortexm-common adjusted documentation
- cortexm_common added eINT dINT defines for now