tag alias: dew -> dew_drop

create alias dew -> dew_drop

not sure why the tag type of the former is an arttag, but all posts are properly identified with artists. the dew in the posts seem to be consistent with the use of dew_drop. requesting an alias and tag type change to gentag. thanks.

EDIT: *sorry for the bump; just testing OP edit*

Done. Except the tagtype change, I don't know how to make something general now. The way I did it before doesn't exist in 2.0 right now.