Since we now require R19, we shouldn't need that anymore.
There are still couple places where p1_time_compat:unique_timestamp() is
used as there is no direct equivalent.
The header consisted of too many unrelated stuff and macros misuse.
Some stuff is moved into scram.hrl and type_compat.hrl.
All macros have been replaced with the corresponding function calls.
TODO: probably type_compat.hrl is not even needed anymore since
we support only Erlang >= OTP 17.5
Paweł Chmielowski