Address David's comments

backend/common/src/id_type.rs

@@ -46,8 +46,8 @@ macro_rules! id_type {
 
 #[cfg(test)]
 mod test {
-    //! Mostly we're just checking that everything compiles OK
-    //! when the macro is used as expected..
+    // Mostly we're just checking that everything compiles OK
+    // when the macro is used as expected..
 
     // A basic definition is possible:
     id_type! {

backend/common/src/rolling_total.rs

@@ -148,7 +148,7 @@ where
         self.total
     }
 
-    /// Fetch the current time source, incase we need to modify it.
+    /// Fetch the current time source, in case we need to modify it.
     pub fn time_source(&mut self) -> &mut Time {
         &mut self.time_source
     }