Fix compilation with gcc 4.5 in C++11 mode

Gcc 4.5 does not allow non-public defaulted functions, so fall back to the C++03 version. Also replaced the deprecated macros with the new ones and adjusted formatting.
Added a new macro BOOST_EXPLICIT_OPERATOR_BOOL_NOEXCEPT, which implements a noexcept operator. Also added explicit noexcept specification for the constexpr macro.
Merge pull request #7 from ericniebler/develop

value_init and swap work on nvidia gpu's
Merge pull request #6 from Lastique/develop

Added a new macro BOOST_EXPLICIT_OPERATOR_BOOL_NOEXCEPT
Merge pull request #5 from Lastique/patch-1

Fix compilation with gcc 4.5 in C++11 mode
Replaced left shift of signed integer values with multiplication to keep the expressions constant according to C++11.
Merge branch 'develop' of github.com:boostorg/utility into develop
Merge commit '991539725e5943b7f280f7ecd7a00aa7f3dc0582'
Merge commit '5ce9683858f5ced8b0df665aad74271dc7c9648d'