Allow '-' char in name of typeface, rather than replacing it with a space char.

Current filter translates "invalid" characters in a typeface (font) name to ' ', restricting "valid" chars to alpha-numeric+space, only; but '-' is a common typeface name. In particular, TypeKit generates names with '-'s. This change allows '-'s.
Merge pull request #1 from wrlee/patch-1

Allow '-' char in name of typeface, rather than replacing it with a spac...