improved delta adding speed i think (todo: run more safety tests on insert_exact)

src/state/local/delta.rs

@@ -79,12 +79,14 @@ impl Delta
 		} else if span.len() == 1  {
 		    inserter.insert(self.location, span[0]);
 		} else if span.len() > 1 {
-		    // reserve the extra space
+		    inserter.insert_exact(self.location, span.iter().copied());
+		    
+		    /*// reserve the extra space
 		    inserter.reserve(span.len());
 		    // shift everything across, replacing with the new values
 		    let splice: Vec<_> = inserter.splice(self.location.., span.iter().cloned()).collect();
 		    // add tail back
-		    inserter.extend(splice);
+		    inserter.extend(splice);*/
 		}
 	    },
 	    _ => unimplemented!(),