This patch adds wrapper methods to allow the user to sign and verify a
single message block without having to go through the multi-step
process of creating a signer or verifier, updating it with the one
message, and finalizing the result. This will make signing and
verifying data more user-friendly when only using small messages.

Partial bug #1529

* Refs #1478 -- attempt to improve our nonsense docs for ECCurve.key_size

* fix

* SSH serialization for public keys

* name errors ahoy!

* id, ego, superego

* dsa support

* EC support

* Don't keyerror

* Documentation OpenSSH

* flake8

* fix

* bytes bytes bytes

* skip curve unsupported

* bytes!

* Move a function

* reorganize code for coverage

* Add alias for Certificate serial as serial number

* Adding deprecation to utils

* Now with catch warnings and proper vers

* add RSA OAEP SHA2 vectors via custom vector creation

* update the docs

* retab

* remove sha2 oaep support (it will be added again in another PR)

* add header to each vector file

* Add Java 8 Bouncy Castle based verification of RSA-OAEP SHA-2 test vectors (#4)

* Update Java verifier to skip past test vector file header if present (#5)

* Update Java verifier to skip past test vector file header if present

* Fix tabs vs. space whitespace

* generate sha1 oaep permutations as well + verify support in java

* address review feedback

* NIST SP 800-108 Counter Mode and Feedback Mode KDF

* CounterKDF unit tests

* Refactor to support multiple key based KDF modes.

* Extracting supported algorithms for KBKDF Counter Mode test vectors

* Adding support for different rlen and counter location in KBKDF

* support for multiple L lengths and 24 bit counter length.

* Adding KBKDF Documentation.

* Refactoring KBKDF to KBKDFHMAC to describe hash algorithm used.

* Fixed #2859 -- document that SHA-1 is the worst

* words words words