fixed VelocyPack bug with non-ASCII characters

Author: Mark

src/main/java/com/arangodb/velocypack/VPackBuilder.java

@@ -611,7 +611,7 @@ private void appendSQLTimestamp(final Timestamp value) {
 	}
 
 	private void appendString(final String value) throws VPackBuilderException {
-		final int length = value.length();
+		final int length = value.getBytes().length;
 		if (length <= 126) {
 			// short string
 			add((byte) (0x40 + length));

src/test/java/com/arangodb/velocypack/VPackBuilderTest.java

@@ -887,4 +887,12 @@ public void addVPackObjectInArray() throws VPackException {
 		}
 	}
 
+	@Test
+	public void nonASCII() {
+		final String s = "·ÃÂ";
+		final VPackSlice vpack = new VPackBuilder().add(s).slice();
+		assertThat(vpack.isString(), is(true));
+		assertThat(vpack.getAsString(), is(s));
+	}
+
 }