buffer-proto5: auto-measure the extrema for M/H

also, introduce a `Time` abstraction and allow for more precisely
simulating just a specific time range.

the Sim-related traits still need updating to better integrate this.

src/render.rs

@@ -646,6 +646,17 @@ impl CsvRenderer {
             state: Mutex::new(Some(CsvState::Reading(reader))),
         }
     }
+    pub fn read_column(self, header: &str) -> Vec<String> {
+        let mut rd = match self.state.into_inner().unwrap() {
+            Some(CsvState::Reading(rd)) => rd,
+            _ => panic!("not reading!"),
+        };
+        let colno = rd.headers().unwrap().iter().position(|it| it == header).unwrap();
+        rd.into_records().map(|items| items.unwrap().get(colno).unwrap().to_owned()).collect()
+    }
+    pub fn read_column_as_f32(self, header: &str) -> Vec<f32> {
+        self.read_column(header).into_iter().map(|s| s.parse().unwrap()).collect()
+    }
 }
 
 impl<S: SampleableSim> Renderer<S> for CsvRenderer {