Bug 946835 part 6: In reftests flexbox-baseline-multi-line-horiz-*, increase some sizes from 18px (arbitrary) to 20px (half the container width) to make upcoming vertical variants simpler. (no review)
Bug 946835 part 7: Add vertical variants of existing reftests for checking the baseline of a multi-line flex container. (no review)

--HG--
rename : layout/reftests/w3c-css/submitted/flexbox/flexbox-baseline-multi-line-horiz-1-ref.html => layout/reftests/w3c-css/submitted/flexbox/flexbox-baseline-multi-line-vert-1-ref.html
rename : layout/reftests/w3c-css/submitted/flexbox/flexbox-baseline-multi-line-horiz-1.html => layout/reftests/w3c-css/submitted/flexbox/flexbox-baseline-multi-line-vert-1.html
rename : layout/reftests/w3c-css/submitted/flexbox/flexbox-baseline-multi-line-horiz-2-ref.html => layout/reftests/w3c-css/submitted/flexbox/flexbox-baseline-multi-line-vert-2-ref.html
rename : layout/reftests/w3c-css/submitted/flexbox/flexbox-baseline-multi-line-horiz-2.html => layout/reftests/w3c-css/submitted/flexbox/flexbox-baseline-multi-line-vert-2.html