KT-805 Auto import on code completion insert (Initial version)

idea/testData/quickfix/autoImports/afterImportSingleFile.kt

@@ -0,0 +1,12 @@
+// "Import Class" "true"
+namespace a
+
+import a.b.M
+
+fun test() {
+    val v = M
+}
+
+namespace b {
+    class M() { }
+}

idea/testData/quickfix/autoImports/beforeImportSingleFile.kt

@@ -0,0 +1,10 @@
+// "Import Class" "true"
+namespace a
+
+fun test() {
+    val v = <caret>M
+}
+
+namespace b {
+    class M() { }
+}