add property::time_series_pointer_wrap and use it in history_storage_type.
rename property::storage_type_wrapper to property::type_wrapper.
add documentation.
introduce property::storage_traits<…>.
rename some types in property::pointer_map_storage.
adding experimental return type wrapping to property::pointer_map_storage.
use template arguments in type wrapper interface for property::pointer_map_storage.
add util/locking_ptr.hpp.
rename template classes in storage_traits: value_type -> stored_type and return_type -> value_type
wrap strored_type into locking_ptr in timeseries_pointer_wrap::value_type<…>.