The old _escaped regex matched any characters not in range from space to
tilde, i.e. from \x20 to \x7e. Therefore it matched all non-ASCII characters,
despite this comment in _EncodeString: "Characters above the ASCII range are
passed through to the output encoded as UTF-8 without any escaping."

This changes the regex to match the same set of ASCII control characters as
before, without matching characters outside the ASCII range.

Patch by Kenneth Bongort <kbongort@google.com>
Review URL: https://codereview.chromium.org/23892016/


git-svn-id: http://gyp.googlecode.com/svn/trunk@1728 78cadc50-ecff-11dd-a971-7dbc132099af