book.s upgrade

[zhong zhao]

1.File name extensions longer than 16 characters can also be fully displayed.

2.Scroll to the right end with no less than 2 characters.

3.When the length of line is longer than 222,  the content at the end will no longer be missed.

[zhong zhao]

1. When the length of filename and ext is more than 16,

the first show bookmark list is not aligned correctly,

but the second,third,forth,... show bookmark list is aligned correctly.