Insert empty lines after functions and properties (KT-4002)

#KT-4002 Fixed

idea/testData/formatter/EmptyLineBetweenFunctions.kt

@@ -0,0 +1,53 @@
+// No lines between
+
+fun f2() {}
+fun f1() {}
+fun f3() = 1
+fun f4() {}
+fun f5() {
+}
+fun f6() = 1
+fun f7() = 8
+
+// One line
+
+fun f2() {}
+
+fun f1() {}
+
+fun f3() = 1
+
+fun f4() {}
+
+fun f5() {
+}
+
+fun f6() = 1
+
+fun f7() = 8
+
+// Two lines between
+fun l1() {}
+
+
+fun l2() {}
+
+
+fun l3() = 1
+
+
+fun l4() {}
+
+
+fun l5() {
+}
+
+
+fun l6() = 1
+
+
+fun l7() = 8
+
+
+
+