Fixes the stacktrace trimming

Ref https://github.com/sbt/sbt/issues/4121
Ref https://github.com/sbt/sbt/pull/4232

internal/util-logging/src/main/scala/sbt/internal/util/ConsoleAppender.scala

@@ -421,7 +421,7 @@ class ConsoleAppender private[ConsoleAppender] (
     }
 
   private def appendTraceEvent(te: TraceEvent): Unit = {
-    val traceLevel = getTrace
+    val traceLevel = if (getTrace < 0) Int.MaxValue else getTrace
     val throwableShowLines: ShowLines[Throwable] =
       ShowLines[Throwable]((t: Throwable) => {
         List(StackTrace.trimmed(t, traceLevel))

internal/util-logging/src/main/scala/sbt/internal/util/MainLogging.scala

@@ -13,15 +13,20 @@ object MainAppender {
   def multiLogger(log: ManagedLogger, config: MainAppenderConfig): ManagedLogger = {
     import config._
     // TODO
-    // console setTrace screenTrace
     // backed setTrace backingTrace
     // multi: Logger
 
-    // val log = LogExchange.logger(loggerName)
     LogExchange.unbindLoggerAppenders(log.name)
     LogExchange.bindLoggerAppenders(
       log.name,
-      (consoleOpt.toList map { _ -> screenLevel }) :::
+      (consoleOpt.toList map { appender =>
+        appender match {
+          case a: ConsoleAppender =>
+            a.setTrace(screenTrace)
+          case _ => ()
+        }
+        appender -> screenLevel
+      }) :::
         List(backed -> backingLevel) :::
         (extra map { x =>
         (x -> Level.Info)

internal/util-logging/src/main/scala/sbt/internal/util/StackTrace.scala

@@ -4,7 +4,7 @@
 package sbt.internal.util
 
 object StackTrace {
-  def isSbtClass(name: String) = name.startsWith("sbt") || name.startsWith("xsbt")
+  def isSbtClass(name: String) = name.startsWith("sbt.") || name.startsWith("xsbt.")
 
   /**
    * Return a printable representation of the stack trace associated