This test catches a few bugs we had in our C++ locale support (see
issue #314). After the previous patches, this test will succeed.

This test verifies that:

1. Trying to use an unsupported locale (we only support "C") throws an
   exception, as required, rather than crashing as before.

2. std::isspace(' ',std::locale) returns true, as it should (previously
   our ctype array was shifted by one, so this returned false!)

3. istream's input operator (operator>>) should stop on a space.
   Previously, it didn't, because we didn't recognize the space.

Signed-off-by: Nadav Har'El <nyh@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>