support for  backface-visibility

add support for backface-visibility ( https://developer.mozilla.org/en-US/docs/Web/CSS/backface-visibility )
ignore *.cache
Merge pull request #53 from oker1/master

ignore *.cache
Merge pull request #49 from builtbylane/patch-1

support for  backface-visibility
Merge remote-tracking branch 'upstream/master'