fix typo in subpixel-utils
Change polygon test refs to use writing modes

This requires more ref files; however, failures were seen with these
tests in Blink when the refs did not use the same writing mode as the
test itself.
Add test for stacked floats with shape-outside
First shape-margin tests.
hg rm-ing in order to submit via gitHub pull request
revising test based on feedback from GT
revising test based on feedback from GT
revising test based on feedback from GT
revising test based on feedback from GT
added new ref file with numbering in name
adding tests for column-fill
removing links from reftests
removing links from reftests; ading links to tests
revising assertion
removing old ref file
revising ref to avoid the use of supporting images
revising ref to avoid the use of supporting images
revising ref to avoid the use of supporting images
revising inset/outset tests; resetting padding on table elements, revising descriptive test (identical -> lool the same), fixing typo
revising inset/outset tests; adding markup to descriptive text, removing some unnecessary declaration in reference files