fix hscript.Bytes with -D hscriptPos (close #64)

.travis.yml

@@ -64,6 +64,7 @@ script:
     haxe build.hxml &&
     popd
   - haxe bin/build-interp.hxml
+  - haxe bin/build-interp.hxml -D hscriptPos
   - haxe bin/build-neko.hxml         && neko bin/Test.n
   - haxe bin/build-js.hxml           && node bin/Test.js
   - haxe bin/build-java.hxml         && java -jar bin/Test.jar

hscript/Bytes.hx

@@ -251,6 +251,10 @@ class Bytes {
 
 	function doDecode() : Expr {
 	#if hscriptPos
+		if (bin.get(pin) == 255) {
+			pin++;
+			return null;
+		}
 		var origin = doDecodeString();
 		var line = doDecodeInt();
 		return { e : _doDecode(), pmin : 0, pmax : 0, origin : origin, line : line };