hair colour renames. read before merging

Previously, hair colour file names were inconsistent across hair styles.
For example, ponytail2/redhead.png was the same colour as swoop/dark-blonde.png, and ponytail2/raven.png was the same as swoop/raven2.png, not swoop/raven.png

This pull request's commit fixes all inconsistencies. The possible downside is that the underlying renames break existing setups.

So please be aware that the present pull request is more intrusive than previous ones.