JS lib: introduced different output strategies, and chose them depending of environment.

#KT-2994 Fixed

js/js.translator/testData/native/cases/print.kt

@@ -0,0 +1,63 @@
+package foo
+
+val EXPECTED = """Hello, World
+
+***
+####
+"""
+
+val EXPECTED_NEWLINE_FOR_EACH = """Hello
+, World
+
+
+
+***
+##
+##
+
+"""
+
+native
+fun eval(code: String): Any? = noImpl
+
+native
+var buffer: String = noImpl
+
+fun test(expected: String, initCode: String, getResult: () -> String) {
+    buffer = ""
+
+    eval("Kotlin.out = new $initCode")
+
+    print("Hello")
+    print(", World")
+    print("\n")
+    println()
+    println("***")
+    print("##")
+    print("##")
+    println()
+
+    val actual = getResult()
+
+    assertEquals(expected, actual, initCode)
+}
+
+fun box(): String {
+    test(EXPECTED, "Kotlin.NodeJsOutput(outputStream)") {
+        buffer
+    }
+
+    test(EXPECTED_NEWLINE_FOR_EACH, "Kotlin.OutputToConsoleLog()") {
+        buffer
+    }
+
+    test(EXPECTED, "Kotlin.BufferedOutput()") {
+        eval("Kotlin.out.buffer") as String
+    }
+
+    test(EXPECTED, "Kotlin.BufferedOutputToConsoleLog()") {
+        buffer
+    }
+
+    return "OK"
+}

js/js.translator/testData/native/native/print.js

@@ -0,0 +1,24 @@
+var buffer = "";
+
+function writeToBuffer(a) {
+    var type = typeof a;
+    if (type !== "string") throw Error("Expected string argument type, but got: " + type);
+
+    buffer += a;
+}
+
+function writelnToBuffer(a) {
+    writeToBuffer(a);
+    writeToBuffer("\n");
+}
+
+var GLOBAL = (0, eval)("this");
+
+GLOBAL.console = {
+    log: writelnToBuffer
+};
+
+GLOBAL.outputStream =  {
+    write: writeToBuffer
+};
+