[bugfix] call setvbuf in pic_file constructor
[bugfix] call setvbuf in pic_file constructor

leavesbnw/picrin,koba-e964/picrin,koba-e964/picrin,omasanori/picrin,dcurrie/picrin,koba-e964/picrin,ktakashi/picrin,ktakashi/picrin,omasanori/picrin,leavesbnw/picrin,picrin-scheme/picrin,picrin-scheme/picrin,leavesbnw/picrin,ktakashi/picrin,dcurrie/picrin