ChangeLog.d/rsa-bitlen.txt

Bugfix
   * Fix mbedtls_pk_get_bitlen() for RSA keys whose size is not a
     multiple of 8. Fixes #868.

Features
   * The new function mbedtls_rsa_get_bitlen() returns the length of the modulus
     in bits, i.e. the key size for an RSA key.