1.3.0

• crypto: support for revocation lists (CRLs)
• dht: add per-ip-range storage ratio. This means a single IP
  or IP range won't be able to exhaust the DHT storage anymore.
  If storage is full, the oldest value of the most consuming IP range
  will be dropped
• dht: drop values as soon as they expire
• dht: better support for multiple listens on a single hash
• dht: various optimisations
• abi: symbols are not exported by default anymore
• build: install in standard GNU directories by default to support
  multi-arch systems
• python: properly check for Cython
• python: small tools updates and fixes