changed platform and applications to microblaze architecture

- platform now creates microblaze processors and uses the microblaze newlib
- application makefile links microblaze_io.c which implements dummy io functions
- updated permissions (execute removed from source files)
added some loosely related test applications (contrib)
added iesr test application
added error handling to sdltest
added event handling to sdltest
fixed stdbool inclusion in sdltest
dlo test application added

does not work yet, dont know why