#208 "set page landscape"

[lyzheng]

This is a problem existing in version 2.12.9.
For old version 2.12.7, when we use command "set
page landscape", the code defaultly provides paper size
as (11x8.5 inches). For new version, we must use
command "set page size" before we use "set page
landscape". New version provide page sizes of (letter,
A4, ...), but page size with 11x8.5 inches is not
included. The option of paper size with 11x8.5 inches
should be include at command "set page size".