ZXingDialog

I refactored ZXing to ZXingDialog, details:

1. ZXingDialog was wraped as a widget, and can be played in a dialog;
2. ZXingDialog min api is 7 instead of 15;
3. ZXingDialog only support QRCode (others decoder was removed);
4. ZXingDialog removes code generator;
5. ZXingDialog change landscape to portrait;
6. ZXingDialog supports 320×240 devices.

Chinese article reference: http://sickworm.com/?p=322

The code did works, but it won't get any support in the future. Hope it helps you and GOOD LUCK.