Fix parsing of microseconds with UTF8 symbol and parsing negative durations

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "hifitime"
-version = "4.0.1"
+version = "4.0.2"
 authors = ["Christopher Rabotin <[email protected]>"]
 description = "Ultra-precise date and time handling in Rust for scientific applications with leap second support"
 homepage = "https://nyxspace.com/"

benches/crit_duration.rs

@@ -10,7 +10,7 @@ pub fn criterion_benchmark(c: &mut Criterion) {
             b.iter(|| {
                 let interval_length_s: f64 = 6311433599.999999;
                 let interval_length: Duration = black_box(interval_length_s * Unit::Second);
-                interval_length.to_parts().1;
+                interval_length.to_parts();
             })
         },
     );

src/duration/mod.rs

@@ -57,11 +57,11 @@ pub mod ops;
 ///
 /// **Important conventions:**
 /// 1. The negative durations can be mentally modeled "BC" years. One hours before 01 Jan 0000, it was "-1" years but  365 days and 23h into the current day.
-/// It was decided that the nanoseconds corresponds to the nanoseconds _into_ the current century. In other words,
-/// a duration with centuries = -1 and nanoseconds = 0 is _a greater duration_ (further from zero) than centuries = -1 and nanoseconds = 1.
-/// Duration zero minus one nanosecond returns a century of -1 and a nanosecond set to the number of nanoseconds in one century minus one.
-/// That difference is exactly 1 nanoseconds, where the former duration is "closer to zero" than the latter.
-/// As such, the largest negative duration that can be represented sets the centuries to i16::MAX and its nanoseconds to NANOSECONDS_PER_CENTURY.
+///     It was decided that the nanoseconds corresponds to the nanoseconds _into_ the current century. In other words,
+///     a duration with centuries = -1 and nanoseconds = 0 is _a greater duration_ (further from zero) than centuries = -1 and nanoseconds = 1.
+///     Duration zero minus one nanosecond returns a century of -1 and a nanosecond set to the number of nanoseconds in one century minus one.
+///     That difference is exactly 1 nanoseconds, where the former duration is "closer to zero" than the latter.
+///     As such, the largest negative duration that can be represented sets the centuries to i16::MAX and its nanoseconds to NANOSECONDS_PER_CENTURY.
 /// 2. It was also decided that opposite durations are equal, e.g. -15 minutes == 15 minutes. If the direction of time matters, use the signum function.
 ///
 /// (Python documentation hints)