Use cppumock for critical sections.

This allows for easier testing.
Check that code in critical section is executed.
Tests breaking from critical section.
Build hot fix.
Enforce mock order for critical section testing.
Clean fix to the build problem.
Merge pull request #31 from antoinealb/master

Use CPPUmock for critical sections.
Use stable version of CppUTest
Add support for variable arguments to PANIC

Now PANIC can be used with printf-like variable arguments, which is
useful to provide more detailed informations about a crash.
Add support for var args in default panic handler
Merge pull request #32 from antoinealb/panic-var-args

Add support for variable arguments to PANIC
Xmalloc: Fail if size == 0
Merge pull request #34 from antoinealb/malloc-fail-zero

Xmalloc: Fail if size == 0
Changed mutex API to static allocation.
Added mutex implementation for uCOS-III.
Added missing include & fix for compiler warning
Implement static allocation of mock mutexes
Fix documentation
Added threading header
Added threading implementation for uCOS-III