Introduce Kotlin language version 1.2

Wherein DEFAULT version is still 1.1, which means that version 1.2 should be configured manually

compiler/cli/cli-common/src/org/jetbrains/kotlin/cli/common/arguments/DefaultValues.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright 2010-2016 JetBrains s.r.o.
+ * Copyright 2010-2017 JetBrains s.r.o.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -29,7 +29,7 @@ open class DefaultValues(val defaultValue: String, val possibleValues: List<Stri
     object StringNullDefault : DefaultValues("null")
 
     object LanguageVersions : DefaultValues(
-            "\"" + LanguageVersion.LATEST.versionString + "\"",
+            "\"" + LanguageVersion.LATEST_STABLE.versionString + "\"",
             LanguageVersion.values().map { "\"${it.versionString}\"" }
     )