### Fixed
- Restore environment when exiting FAPIConfig

### Added
- Add a context manager for ESYS handles, which flushes the handle at exit.
- Add SVN, ACT and other missing constants.
- Add the ESAPI command `certify_x509`.
- Add the ESAPI command `act_set_timeout`.
- Add copy dunder for cryptography private keys.
- Add the ESAPI command `trsess_get_attributes`.
- Add signature scheme structures.
- Add marshal/unmarshal structures for `TPM2_HANDLE`.
- Add the command_parser module, which can decode TPM 2.0 command/response byte streams.
- Add support for passing prehashed data to `TPMT_SIGNATURE.verify_signature`.
- Add the marshal/unmarshal methods to union types, as they require a selector.
- Add the equal dunder to struct types, allowing comparing two different instances of the same type.

### Changed
- Make the symmetric argument to `start_auth_session` optional.
- Accept None for the pcr_digest argument for `policy_pcr`.
- Support looking up EK templates by other names, such as `L-1` or `H-2`.
- Make the validition ticket for the sign command optional, defaults to a NULL ticket.
- The argument order for `ESAPI.policy_signed`, `ESAPI.policy_ticket` and `ESAPI.policy_authorize` has changed.
  This is to make expiration, nonce_tpm, policy_ref and cp_hash_a arguments optional, with expiration being set to the max value and the rest are empty buffers by default.

### Removed
- Remove support for the tools encoder/decoder.