Revert "Revert "Merge pull request #1766 from Wikia/BAC-709""

This reverts commit c4418ef5868032bd2b0d64d6b32e91fe7c64d88f.
Revert "Revert "Merge pull request #1868 from Wikia/DAR-2623""

This reverts commit a7472749868339df5af88b9ac1cea3707aededc9.
BAC-945 allow domain sharding in dev
BAC-709 account for domain sharding in prod/dev when figuring out a sass file path
added unit tests and change sharding identifier for dev boxes
Merge pull request #1896 from Wikia/BAC-709+945

fixes for sass concat.