Merge pull request scala#4579 from lrytz/swing-2.0.0-M2

Bump swing version to 2.0.0-M2

Author: adriaanm

versions.properties

@@ -24,7 +24,7 @@ scala.binary.version=2.12.0-M1
 # external modules shipped with distribution, as specified by scala-library-all's pom
 scala-xml.version.number=1.0.4
 scala-parser-combinators.version.number=1.0.4
-scala-swing.version.number=1.0.2
+scala-swing.version.number=2.0.0-M2
 jline.version=2.12.1
 scala-asm.version=5.0.3-scala-3