* Implement unit tests for key expression fidelity to user input for hardened paths
* Create HardenedType, rework BIP32Node to take Option[HardenedType] as a parameter
* Fix docs
* An initial (not yet working) implementation with test
* Added custom (non-bip-340) verification for now
* Made KeySet a case class
* Got MuSig2 working with BIP340 verification passing
* Responds to Ben's review
* Fixed hash tags and added parital signature verification
* Added point multiplication that allows infinity and did some refactoring
* Refactored type defs into case classes
* Added tests for more signers and fixed single-party bug
* Added key aggregation test vectors from BIP
* Added nonce generation test vectors from BIP
* Added nonce aggregation test vectors from BIP
* Made nonce aggregation test vectors pass by having MultiNoncePub wrap SecpPoints
* Added remaining static test vectors from BIP
* Implements tweaking support and adds tests, including all of the remaining BIP tests
* Added factory objects for nonce types
* Refactored things into multiple files with renaming and restructuring
* Some minor renaming
* Introduced ParityMultiplier ADT to remove unneccesary computations
* Added scaladocs
* Added messages to invariants
* Fixed a typo
* Nonce generation now takes a SchnorrPublicKey instead of raw bytes
* Made point multiplication more robust
* Responded to Ben nits
* Added musig.md
* Added crypto project and decoupled BitcoinSLogger from NetworkElement
Decoupled BitcoinSLogger from Factory
Moved NetworkElement into crypto project
Moved Factory and BitcoinSUtil (renamed to BytesUtil) to crypto project
Moved MaskedToString to crypto project
Added BytesUtil to imports and cleaned up CryptoUtil.recoverPoint
Moved the rest of crypto stuff to the crypto project
Moved crypto tests to crypto-test project
* Added documentation for crypto project
