Fix build with libc++
Fix build with libc++

Include at least one header (ciso646) so that _LIBCPP_VERSION is defined
and we can make use of it.  Otherwise, we include <tr1/memory> by mistake
which is just a link to <memory> without providing the tr1 namespace.

Found under FreeBSD 10.0-ALPHA5 using clang++ and libc++.

rodrigc/kyua,jmmv/kyua,jmmv/kyua,rodrigc/kyua,jmmv/kyua,rodrigc/kyua,rodrigc/kyua,jmmv/kyua