ADD: added task idle (under define)

Signed-off-by: Giuseppe Monteleone <info@ing-monteleone.com>
ADD: added Yield. Improved debug

Signed-off-by: Giuseppe Monteleone <info@ing-monteleone.com>
ADD: added come comment in makefile, added alias for cortex-m0plus, better option for optimization

Signed-off-by: Giuseppe Monteleone <info@ing-monteleone.com>
FIX: correct behavior for syscall DO_CHECK_MUTEX. Changed name form DO_CHECK_MUTEX to DO_TRY_MUTEX

Signed-off-by: Giuseppe Monteleone <info@ing-monteleone.com>
ADD: added documentation

- rewrite of readme.md file
- minor change to createTask function. Now we pass pure stack size.

Signed-off-by: Giuseppe Monteleone <info@ing-monteleone.com>