* Split assembler routines into -cosmic.s and -iar.s.
* Split Cosmic and IAR specific code using __CSMC__ and __IAR_SYSTEMS_ICC__.
* Context-switch virtual registers on IAR.
* Add detailed description of IAR context-switch scheme.
* Add sample IAR project.
* Add support for IAR to STM8S peripheral driver modules.
* Fix EWSTM8 compiler warnings.