Update CSL-Ruby gem
Add spec to detect unused macros

Applied to all independent styles. Styles can be excluded
from this test by adding their id to the UNUSED_MACROS_FILTER
list.
Delete more unused macros
Remove leftover XML comments
Merge pull request #1086 from inukshuk/remove-unused-macros

Remove unused macros
Remove more unused macros
Put CMoS styles on skip list for unused-macro check
Merge branch 'remove-unused-macros'