Finish OTCrypto. Also abstracted OTMint/OTToken
in a similar way for Lucre library.

Signed-off-by: FellowTraveler <F3llowTraveler@gmail.com>
(Not done) adding Credentials to Nyms.

Signed-off-by: FellowTraveler <F3llowTraveler@gmail.com>
(Still not done yet) Adding credentials to Nyms.

Signed-off-by: FellowTraveler <F3llowTraveler@gmail.com>
(Not done yet) Still adding credentials to Nyms.

Signed-off-by: FellowTraveler <F3llowTraveler@gmail.com>
Credentials seem done! Unit tests are working…

Signed-off-by: FellowTraveler <F3llowTraveler@gmail.com>
v0.88.f: Credentials (done.)

Signed-off-by: FellowTraveler <F3llowTraveler@gmail.com>