Bug fix: token validation failure

- When the JwtSecurityTokenHandler validates a token, it will have a
different behaviour wether you pass a token string or a
JwtSecurityToken. In the latter case, it will reencode the token instead
of using the initial one (RawData), which will have the side effect of
stripping out the CR/LF chars and thus produce a different signature!
- updated NuGet package System.IdentityModel.Tokens.Jwt to latest
version 3.0.2
updated project versions
Merge pull request #4 from cbcrc/master

Bug fix: token validation failure
slight bit of clean-up to make better use of the IJwtSecurityToken interface
Merge branch 'master' of github.com:ICantThinkOfAGoodUserName/JwtAuthForWebAPI into brian
merging in pull request; making a few changes along the way
Merge branch 'brian'
increment version
adding better support for shared key signatures