Fix that let's JwtSecurityTokenHandlerWrapper call ValidateToken with original jwt payload

Uses new 3.0.0.0 Microsoft JSON Token Handler and
it has a fix that passes jwt.RawData to the Microsoft ValidateToken()
Method in order to bypass original behavior that passes JwtSecurityToken
which is free of escapes and therefore leads to validation errors if
incoming jwt token has escapes!

Please take a look at issue #141

Many thanks for taking a look into this!

Regards
Luciano