Program sfmlm | 2D Multistage median filtering. 
[SYNOPSIS]
sfmlm < in.rsf > out.rsf nfw= boundary=n
[PARAMETERS]
bool    | boundary | =n |  [y/n] | 	if y, boundary is data, whereas zero
int     | nfw | = |   | 	filter-window length (positive and odd integer)
[DIRECTORY]
user/yliu
