Prepare scripting infrastructure for REPL:

- refactor script compiler to simplify extending it for repl
- add repl snippet compilation functions to the new scripting compiler
- extract util functions into appropriate files
- extract repl part into separate class
- extract bridge definition and related definitions into separate file

compiler/cli/cli-common/src/org/jetbrains/kotlin/cli/common/repl/ReplState.kt

@@ -61,6 +61,10 @@ interface IReplStageState<T> {
     fun <StateT : IReplStageState<*>> asState(target: Class<out StateT>): StateT =
         if (target.isAssignableFrom(this::class.java)) this as StateT
         else throw IllegalArgumentException("$this is not an expected instance of IReplStageState")
+
+    fun dispose() {
+        history.reset()
+    }
 }