Setting an appropriate sizehint for format in Logging, and removing a superfluous FIXME

akka-actor-tests/src/test/scala/akka/dispatch/FutureSpec.scala

@@ -874,7 +874,6 @@ class FutureSpec extends AkkaSpec with Checkers with BeforeAndAfterAll with Defa
 
         val l1, l2 = new TestLatch
         val complex = Future() map { _ ⇒
-          //FIXME implement _taskStack for Futures
           val nested = Future(())
           nested foreach (_ ⇒ l1.open())
           FutureSpec.ready(l1, TestLatch.DefaultTimeout) // make sure nested is completed

akka-actor/src/main/scala/akka/event/Logging.scala

@@ -848,7 +848,7 @@ trait LoggingAdapter {
   }
 
   def format(t: String, arg: Any*): String = {
-    val sb = new StringBuilder //FIXME add some decent size hint here
+    val sb = new StringBuilder(64)
     var p = 0
     var rest = t
     while (p < arg.length) {