[css-gcpm-3] fix error in string-set-005.xht; add more tests to work-in-progress
merge

--HG--
rename : css-gcpm-3/string-set-005.xht => css-gcpm-3/string-set-005.html
rename : css-gcpm-3/string-set-009.xht => css-gcpm-3/string-set-009.html