Accept both byte arrays and buffers (closes #15)

nbt.js

@@ -108,7 +108,8 @@
 		this[nbt.tagTypes.byteArray] = function(value) {
 			this.int(value.length);
 			accommodate(value.length);
-			value.copy(this.buffer, this.offset);
+			var valueBuffer = 'copy' in value ? value : new Buffer(value);
+			valueBuffer.copy(this.buffer, this.offset);
 			this.offset += value.length;
 			return this;
 		};

sample/bigtest.js

@@ -123,7 +123,7 @@ module.exports = {
         },
         "byteArrayTest (the first 1000 values of (n*n*255+n*7)%100, starting with n=0 (0, 62, 34, 16, 8, ...))": {
             "type": "byteArray",
-            "value": new Buffer([
+            "value": [
                 0,
                 62,
                 34,
@@ -1124,7 +1124,7 @@ module.exports = {
                 74,
                 6,
                 48
-            ])
+            ]
         },
         "doubleTest": {
             "type": "double",

test/writer-spec.js

@@ -61,7 +61,7 @@ describe('nbt.Writer', function() {
 		expect(writer.double(1).buffer).to.deep.equal(buffer);
 	});
 
-	it('writes 8-bit byte arrays', function() {
+	it('writes 8-bit byte arrays from buffers', function() {
 		var writer = new nbt.Writer();
 		var buffer = new Buffer([
 			0,0,0,2, 1,2,
@@ -71,6 +71,16 @@ describe('nbt.Writer', function() {
 		expect(writer.byteArray(new Buffer([3, 4, 5, 6])).buffer).to.deep.equal(buffer);
 	});
 
+	it('writes 8-bit byte arrays from plain arrays', function() {
+		var writer = new nbt.Writer();
+		var buffer = new Buffer([
+			0,0,0,2, 1,2,
+			0,0,0,4, 3,4,5,6
+		]);
+		expect(writer.byteArray([1, 2]).buffer).to.deep.equal(buffer.slice(0, 6));
+		expect(writer.byteArray([3, 4, 5, 6]).buffer).to.deep.equal(buffer);
+	});
+
 	it('writes 32-bit int arrays', function() {
 		var writer = new nbt.Writer();
 		var buffer = new Buffer([