updated for version 7.4.476
Problem:    MingW: compiling with "XPM=no" doesn't work.
Solution:   Check for the "no" value. (KF Leong)  Also for Cygwin. (Ken
	    Takata)
Added tag v7-4-476 for changeset 4c29b75cae19
updated for version 7.4.477
Problem:    When using ":%diffput" and the other file is empty an extra empty
	    line remains.
Solution:   Set the buf_empty flag.
Added tag v7-4-477 for changeset f21a2f67bdbb