[v3 patch] Fix some Filesystem TS operations

[Jonathan Wakely]

On 15/05/15 19:37 +0100, Jonathan Wakely wrote:
>I've also made filesystem::temp_directory_path() check the TMP,
>TEMPDIR and TEMP environment variables, as suggested in
>[fs.op.temp_dir_path] at
>http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4099.html#fs.op.temp_dir_path
>rather than my original implementation which only checked TMPDIR
>(because I think that's the only one mentioned by POSIX). I'm not
>unsure whether it's better to follow the non-normative note or only
>check for the POSIX name. Anyone else have any thoughts?

Oops, unintended double negative. I meant I'm unsure.