change if/else style
change if/else style, change default behavior of set_margin (CSI r)
change if/else style
change if/else style
change if/else style
change if/else style
change struct cell_t *cells - > *cells
change struct cell_t *cells - > *cells
change if/else style, change struct cell_t *cells - > *cells
add LAZY_DRAW
change if/else style, change struct cell_t *cells -> **cells, add vertical synchronizing
change if/else style, change struct cell_t *cells -> **cells, refer SHELL env, remove SIGWINCH, change xredraw() and xresize()