fix for issue 8111 exclude .sass-cache folder in project view

adds the `.sass-cache` folder to the list of files and folders excluded from view in the project tree.

addresses issue #8111 
Personally I don't care about alphabetizing this, but SyncArchive/SyncID/SyncIgnore are sort of a related set so it feels weird to stick this new entry in the middle of them.  We should either add it at the end, or before them.