Cleanup scripted tests

The sleeps in source-dependencies/export-jars are no longer necessary
and just slow the test down. I also fixed minor syntax issues in
scala-instance-classloader and fixed a thread leak in the test.

sbt/src/sbt-test/source-dependencies/export-jars/test

@@ -5,11 +5,9 @@ $ copy-file changes/A1.scala a/A.scala
 $ copy-file changes/A2.scala a/A.scala
 
 # done this way because last modified times often have ~1s resolution
-$ sleep 2000
 > run 2
 $ copy-file changes/A3.scala a/A.scala
 
-$ sleep 2000
 > run 3
 
 $ copy-file changes/build2.sbt build2.sbt
@@ -19,9 +17,7 @@ $ copy-file changes/A1.scala a/A.scala
 > run 1
 $ copy-file changes/A2.scala a/A.scala
 
-$ sleep 2000
 > run 2
 $ copy-file changes/A3.scala a/A.scala
 
-$ sleep 2000
 > run 3

sbt/src/sbt-test/tests/scala-instance-classloader/src/test/scala/Test.scala

@@ -10,11 +10,10 @@ class BadTest {
     // * Load something from our own classloader that's INSIDE the scala library
     // * Try to load that same something from the THREAD CONTEXT classloader.
     // * Ensure we can do both, i.e. the second used to be filtered and broken.
-    val current = Thread.currentThread.getContextClassLoader
-    val mine = this.getClass.getClassLoader
     val system = ActorSystem()
     def evilGetThreadExectionContextName =
       system.asInstanceOf[ActorSystemImpl].internalCallingThreadExecutionContext.getClass.getName
+    system.terminate()
     val expected = "scala.concurrent.Future$InternalCallbackExecutor$"
     Assert.assertEquals("Failed to grab appropriate Akka name", expected, evilGetThreadExectionContextName)
   }