Check for CROSSWORKS also.
Do not include headers from sys.

Fixes CROSSWORKS compilation problems.
Fix compilation with CROSSWORKS.
Allow the file compile with CROSSWORKS.
Make these compile with CROSSWORKS.
Merge branch 'master' of c:/work/git/mbed
Add non-working project file.
Fix the project file.
Add a simple main.
Define NULL as 0.
Merge branch 'master' of github.com:tkoskine/mbed