Supported excluded packages/classes in completion.

#KT-2413 in progress

idea/idea-completion/testData/basic/multifile/ExcludedJavaClass/ExcludedJavaClass.kt

@@ -0,0 +1,4 @@
+val x = Ex<caret>
+
+// ABSENT: ExcludedClass
+// EXIST: ExtraClass

idea/idea-completion/testData/basic/multifile/ExcludedJavaClass/somePackage/ExcludedClass.java

@@ -0,0 +1,5 @@
+package somePackage;
+
+public class ExcludedClass {
+
+}

idea/idea-completion/testData/basic/multifile/ExcludedJavaClass/somePackage/ExtraClass.java

@@ -0,0 +1,5 @@
+package somePackage;
+
+public class ExtraClass {
+
+}