Fix Psych::SyntaxError and other data issues.

x00: "found unknown escape character while parsing a quoted scalar at line 2 column 3"
x02: "found character that cannot start any token while scanning for the next token at line 189 column 3"
x09: Psych interprets string matching /^on$/i as +true+
x0a: ditto
x0f: Syck interprets ".5" as string, not float 0.5
x22: "did not find expected alphabetic or numeric character while scanning an alias at line 25 column 3"