Added a constructor to timespec_duration, real_timespec_timepoint, and mono_timespec_timepoint that takes an intmax_t representing the number of nanoseconds in the timespec.
Added a getNs() function to timespec_duration, real_timespec_timepoint, and mono_timespec_timepoint that returns an intmax_t representing the number of nanoseconds in the timespec.
Added a timespec_milliseconds() function that takes an integer representing milliseconds and returns a timespec_duration.
Removed some unnecessary BOOST_SYMBOL_VISIBLE declarations.
Removed the unnecessary d100 variable declarations.