Cookie.PREF handler enhance
1. first visiting without cookie, LD will be set to zh-CN, NW will be set to 1
2. the following visiting with cookie, LD and NW will keep the origin settings
3. then, the preferences page works properly.
Request cookie handle enhance, wipe off the annoying suffix of url
Accept-Encoding rules update.
1. It is set to empty when proxy to backend google only.
2. The body that send back to client can be compressed properly.
Add chinese README and issues#5 fixed