Say a stale file is dropped only once it is stale on every machine

src/noldova.context.testing/src/api/index.d.ts

@@ -842,7 +842,8 @@ export declare class TestFileTiming {
   public readonly isOver: boolean;
 
   /**
-   * True when the suite lists the file but its median is within the time an unlisted file may take, so the list should drop it.
+   * True when the suite lists the file but its median on this machine is within the time an unlisted file may take. A list measured on
+   * several machines drops the file only once it is stale on every one of them.
    */
   public readonly isStale: boolean;
 

src/noldova.context.testing/src/resources.ts

@@ -242,7 +242,7 @@ export class Resources {
   }
 
   public static fileTimingStale(file: string, median: string, budgetLimitMilliseconds: number): string {
-    return `Stale: ${file}, median ${median}, within the ${Math.round(budgetLimitMilliseconds)} ms an unlisted file may take; drop it from the list.`;
+    return `Stale: ${file}, median ${median}, within the ${Math.round(budgetLimitMilliseconds)} ms an unlisted file may take on this machine; the list drops it once it is stale on every machine the list was measured on.`;
   }
 
   public static fileTimingWithin(file: string, median: string, limitMilliseconds: number): string {

src/noldova.context.testing/tests/models/timing/test-file-timing.test.ts

@@ -34,7 +34,8 @@ export class TestFileTimingTests {
     const unlisted = new TestFileTiming("Sample/a.test.js", 900, 1200, 1200, false);
 
     Assert.areEqual("true,false,false", [stale.isStale, slower.isStale, unlisted.isStale].join());
-    Assert.areEqual("Stale: Sample/fast.test.js, median 1200 ms, within the 1200 ms an unlisted file may take; drop it from the list.", stale.format());
+    Assert.areEqual("Stale: Sample/fast.test.js, median 1200 ms, within the 1200 ms an unlisted file may take on this machine; "
+      + "the list drops it once it is stale on every machine the list was measured on.", stale.format());
     Assert.areEqual("Within: Sample/slow.test.js, median 1201 ms, limit 3000 ms.", slower.format());
     Assert.areEqual("Within: Sample/a.test.js, median 900 ms, limit 1200 ms.", unlisted.format());
   }