Avoid using auto_ptr

[brycelelbach]

[reported by hkaiser] [Trac time Wed Sep 21 11:16:55 2011] auto_ptr is deprecated in C++11, let's replace it with either boost::scoped_ptr or std::unique_ptr.

[brycelelbach]

[comment by hkaiser] [Trac time Wed Sep 21 14:21:39 2011] Fixed in rev. [5526]

[brycelelbach]

[comment by hkaiser] [Trac time Wed Sep 21 14:40:36 2011] Reopening... boost::scoped_ptr can't be used as it does not expose a release() method. We need to have some means of deciding whether std::unique_ptr is available and use that instead.

[brycelelbach]

[comment by hkaiser] [Trac time Wed Sep 21 15:09:33 2011] Fixed in code in rev. 5244a53 by relying on a pp constant HPX_USE_UNIQUE_PTR. We need to add build system support for this (see #135).