Implemented clock_time_conversion<D, local_t> calling D::from_local
and clock_time_conversion<locat_t, S> calling S::to_local.
To avoid ambiguities addes:
* clock_time_conversion<local_t, local_t> - idenitity
* clock_time_conversion<local_t, utc_clock> - same as default (utc_clock::to_local)
* clock_time_conversion<utc_clock, local_t> - same as default (utc_clock::from_local)
In addition, as std::chrono::system_clock cannot be edited, added:
* clock_time_conversion<local_t, std::chrono::system_clock> - assumes same epoch
* clock_time_conversion<std::chrono::system_clock, local_t> - assumes same epoch
They will be required to resolve amibiguity anyway.
Tomasz Kamiński
9f1c4b0110