* Collecting PEM -> DER conversions.
* Using cryptography instead of OpenSSL binary in some situations.
* Moving key-to-disk writing for key content to parse_account_key.
* Rename parse_account_key -> parse_key.
* Move OpenSSL specific code for key parsing and request signing into global functions.
* Also using cryptography for key parsing and request signing.
* Remove assert statements.
* Fixing handling of key contents for cryptography code path.
* Allow to disable the use of cryptography.
* Updating documentation.
* 1.5 seems to work as well (earlier versions don't have EC sign function). Making Python 2.x adjustments.
* Changing option to select_crypto_backend.
* Python 2.6 compatibility.
* Trying to test both backends separately for acme_account.
* Also testing both backends separately for acme_certificate and acme_certificate_revoke.
* Adding changelog entry which informs about select_crypto_backend option in case autodetect fails.
* Fixing YAML.
