Commit 2013.10.04 -- minor TR1 improvements.

Added support for `hash<>` with native-type, pointer, string and wstring
specializations (still missing is `shared_ptr<T>` specialization).

Fixed some details in code calls in random's implementation in `detail_seed`.

Added support for up to 4 or 5 arguments in `function<>` and cleaned the
code for `bad_function_call`.

Tested in GCC 4.7 and MSVC 8. Tests in clang and GCC 4.4 still pending.