[CMake] Ignore library flags now works in 2.4.8!

[Sylvain Benner]

> I don't see how that SET does anything other than set a variable.  It 
> must be how your project uses that variable. 
> VS_MULTITHREADED_DEBUG_IGNORE_LIBRARY_FLAGS is not a variable that 
> CMake looks at...  2.4.8 did fix the problem with multiple 
> /NODEFAULTLIB lines not working.
>
Seems like my last reply is a bit off-topic then ;-)
Sorry for this.

--Sylvain