added strcat builtin

samples/deepfailure.noja

@@ -1,12 +1,14 @@
 
-depth = 9;
-
-fun fail(p)
+fun fail_at_depth(depth)
 {
-	if p < depth:
-		fail(p+1, depth, fail);
-	else
-		assert(false);
+	fun fail(current_depth)
+	{
+		assert(current_depth < depth);
+		fail(current_depth + 1);
+	}
+
+	fail(0);
 }
 
-fail(0);
+
+fail_at_depth(9);

samples/strcat.noja

@@ -0,0 +1,22 @@
+
+A = 'Hello';
+B = ', ';
+C = 'world';
+D = strcat(A, B, C);
+
+fun append_esclamation_mark(A, n)
+{
+	if n == none:
+		n = 1;
+	
+	i = 0;
+	while i < n:
+		{
+			A = strcat(A, '!');
+			i = i + 1;
+		}
+
+	return A;
+}
+
+print(append_esclamation_mark(D, 7), '\n');