INSTALL.Windows: Add a TODO for QOS.

Also, remove the entry that talks about the need for atomic support
on Windows as that has already been added.

Signed-off-by: Gurucharan Shetty <gshetty@nicira.com>
Acked-by: Ben Pfaff <blp@nicira.com>
Acked-by: Nithin Raju <nithin@vmware.com>
tests: Skip a sflow test for Windows.

AT_XFAIL_IF cannot be used here because it lets the tests
run first and then say that the failure is expected. In this
particular test, the utilities simply hang blocking all
other tests. So use AT_SKIP_IF instead.

Signed-off-by: Gurucharan Shetty <gshetty@nicira.com>
Acked-by: Ben Pfaff <blp@nicira.com>
Acked-by: Nithin Raju <nithin@vmware.com>