Don't throw DeserializationException for U+007F to U+009F

These are acceptable characters per RFC4627 section 2.5:

> All Unicode characters may be placed within the
> quotation marks except for the characters that must be escaped:
> quotation mark, reverse solidus, and the control characters (U+0000
> through U+001F).
Merge pull request #29 from jscheid/accept-high-control

Don't throw DeserializationException for U+007F to U+009F