Undoing some much too hacky code to implement a...

Undoing some much too hacky code to implement a -jar option and then
following wherever that led me. Tangible results include:

 * much beautified scala -help, including documenting some things
   never before documented in this plane of existence
 * an improved Jar abstraction
 * further systemization of system properties

In addition, the jars created by -savecompiled are given the right
manifest so the jar is runnable. That means you can:

  scala -savecompiled bippy.scala arg1 arg2
  scala -jar bippy.scala.jar arg1 arg2

And both lines should yield the same result. No review.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/compiler/scala/tools/nsc/io/SourceReader.scala b/src/compiler/scala/tools/nsc/io/SourceReader.scala
index 86c986763e..7c9b776eb3 100644
--- a/src/compiler/scala/tools/nsc/io/SourceReader.scala
+++ b/src/compiler/scala/tools/nsc/io/SourceReader.scala
@@ -7,7 +7,7 @@
 package scala.tools.nsc
 package io
 
-import java.io.{ FileInputStream, InputStream, IOException, File => JFile }
+import java.io.{ FileInputStream, InputStream, IOException }
 import java.nio.{ByteBuffer, CharBuffer}
 import java.nio.channels.{FileChannel, ReadableByteChannel, Channels}
 import java.nio.charset.{CharsetDecoder, CoderResult}