updated for version 7.4.226
Problem:    Cursurline highlighting not redrawn when scrolling. (John
	    Marriott)
Solution:   Check for required redraw in two places.
Added tag v7-4-226 for changeset b650f2db8f96
updated for version 7.4.227
Problem:    Can't build with Ruby 1.8.
Solution:   Do include a check for the Ruby version. (Ken Takata)
Added tag v7-4-227 for changeset b0a9df477096