Move StdTimeout to ectool under std feature

tool/src/timeout.rs

@@ -1,3 +1,6 @@
+#[cfg(feature = "std")]
+use std::time::{Duration, Instant};
+
 #[macro_export]
 macro_rules! timeout {
     ($t:expr, $f:expr) => {{
@@ -25,3 +28,30 @@ pub trait Timeout {
     fn reset(&mut self);
     fn running(&self) -> bool;
 }
+
+#[cfg(feature = "std")]
+pub struct StdTimeout {
+    instant: Instant,
+    duration: Duration,
+}
+
+#[cfg(feature = "std")]
+impl StdTimeout {
+    pub fn new(duration: Duration) -> Self {
+        StdTimeout {
+            instant: Instant::now(),
+            duration
+        }
+    }
+}
+
+#[cfg(feature = "std")]
+impl Timeout for StdTimeout {
+    fn reset(&mut self) {
+        self.instant = Instant::now();
+    }
+
+    fn running(&self) -> bool {
+        self.instant.elapsed() < self.duration
+    }
+}