Base sheets: Rename to default
Done to avoid confusion with theme of the same name in master
GCWU: wrapped IE default-desktop-images in IE classes

Might need some  correction once merged to master
Merge pull request #1212 from nschonni/rename-base-scss-files

Base sheets: Rename to default
Merge pull request #1214 from nschonni/ie-indent-gcwu-desktop-images

GCWU: wrapped IE default-desktop-images in IE classes
Resolved merge conflict and extended base file renaming to WET and Base themes.
Extended base file renaming to remaining theme files.