Add support for the WLCG profile

[bbockelm]

This adds support for the WLCG profile, in addition to a number of tools to help in the testing of tokens.

One can now do the following:

export TOKEN=$(./scitokens-create --cred test.pem --key test.pem --keyid 1 --issuer https://demo.scitokens.org --claim 'scp=read:/' --claim foo=bar --profile scitokens2)

./scitokens-verify  --keyid 1 --issuer https://demo.scitokens.org --cred test.pem $TOKEN

(Even without WiFi!)

[bbockelm]

Oh, and to create the EC file:

openssl ecparam -name prime256v1 -genkey -noout -out test.pem
openssl ec -in test.pem -pubout >> test.pem

[djw8605]

All looks good to me. Did you build it on macos? Is that why there is that mac RPATH change?

[bbockelm]

Yup - we currently have a CMake obsoletion warning on Mac OS X when you run modern versions of cmake. I guess new versions change the default value of this option and they now want you to set things explicitly? ON is the new default IIRC.