KT-1426 Implement "Optimize Imports" in plugin - tests and small fix for aliases.

idea/testData/editor/optimizeImports/WithAliases.kt

@@ -0,0 +1,10 @@
+import java.util.ArrayList
+import java.util.ArrayList as SomeThing
+import java.io as JavaIO
+import java.io.*
+
+class Action {
+    fun test() {
+        val test : ArrayList<Int>? = null
+    }
+}