cleanup string parser, correct errors in backslash escaping
cleanup string parser, correct errors in backslash escaping

fengjian/libinjection,dijkstracula/libinjection,dijkstracula/libinjection,dijkstracula/libinjection,dijkstracula/libinjection,fengjian/libinjection,fengjian/libinjection,ppliu1979/libinjection,ppliu1979/libinjection,ppliu1979/libinjection,fengjian/libinjection,dijkstracula/libinjection,fengjian/libinjection,fengjian/libinjection,ppliu1979/libinjection,ppliu1979/libinjection,fengjian/libinjection,dijkstracula/libinjection,ppliu1979/libinjection