SI-6419 Repl save session command

A simple save command to write out the current replay stack.

```
scala> val i = 7
i: Int = 7

scala> val j=  8
j: Int = 8

scala> i * j
res0: Int = 56

scala> :save multy.script

scala> :q
apm@mara:~/tmp$ cat multy.script
val i = 7
val j=  8
i * j
apm@mara:~/tmp$ skala
Welcome to Scala version 2.11.0-20130626-204845-a83ca5bdf7 (OpenJDK 64-Bit Server VM, Java 1.7.0_21).
Type in expressions to have them evaluated.
Type :help for more information.

scala> :load multy.script
Loading multy.script...
i: Int = 7
j: Int = 8
res0: Int = 56

scala> :load multy.script
Loading multy.script...
i: Int = 7
j: Int = 8
res1: Int = 56
```

1 files changed, 16 insertions, 0 deletions

diff --git a/test/files/run/repl-save.scala b/test/files/run/repl-save.scala
new file mode 100644
index 0000000000..465aff225b
--- /dev/null
+++ b/test/files/run/repl-save.scala
@@ -0,0 +1,16 @@
+import scala.tools.partest.ReplTest
+
+object Test extends ReplTest {
+  def code = s"""
+    |val i = 7
+    |val j = 8
+    |i * j
+    |:save $saveto
+  """.stripMargin.trim
+  def saveto = testOutput / "session.repl"
+
+  override def show() = {
+    super.show()
+    Console print saveto.toFile.slurp
+  }
+}