[Aux] Ignore const, & and && modifiers when determining is type `T` convertible to attribute.
[API] Additional implicit integer convert ions. Only implicit conversion from long is not supported at this moment.
[API] Now objects with overloaded `std::ostream operator<<` can be passed through emplace pack in logging macro.
[Tests] Updating tests. Also slightly refactoring done.
[Code style] Naming.
[Aux] Trait `are_same` now inherits `std::true_type` or `std::false_type` in all cases.
[Code style] Package decomposition done.
[GCC 4.4] Fix warning.
[GCC 4.4] Backport for declval.
[Code style] Inheriting from `are_same` instead of using it results in more flexible class.
[Code style] Comments styling.
[Aux] Drop `long long` implicit conversion support, because it isn’t portable.