Re; System stdlibs [Related? to: STLport-cleanup branch]

[Pedro F. Giffuni via dev]

 Hi Arrigo;
I honestly don't know .. .it may be for windows (mingw?).
I now see there are some mismatches in the STLport removal as done in  my 
experimental compilers-101 branch. The STLport branch will need testing on both 
Linux/unix and Windows, which is part of why I am not spending time on it. :-/
The build system is a beast.
Pedro.