Refactor CompileKotlinAgainstKotlinTest

CKAKTest is now abstract, the actual testcases are generated via GenerateTests
into CompileKotlinAgainstKotlinTestGenerated.

Also invokeMain() now invokes namespace.main instead of bbb.namespace.main.

compiler/testData/compileKotlinAgainstKotlin/DefaultConstructor.A.kt

@@ -1 +1,3 @@
+package aaa
+
 class A(val a: Int = 1)

compiler/testData/compileKotlinAgainstKotlin/DefaultConstructor.B.kt

@@ -1,5 +1,3 @@
-package bbb
-
 fun main(args: Array<String>) {
-    A()
+    aaa.A()
 }

compiler/testData/compileKotlinAgainstKotlin/Simple.B.kt

@@ -1,9 +1,6 @@
-package bbb
-
 fun main(args: Array<String>) {
     val h = aaa.hello()
     if (h != 17) {
         throw Exception()
     }
-    System.out?.println("It is 17!")
 }