Release v4.8.1

Release v4.8.0

Bump version number to 4.7.1 for bugfix release

Merge pull request zeromq#399 from gummif/gfa/message-ctor

Problem: message_t ctor string inconsistency

Merge pull request zeromq#374 from gummif/patch-2

Problem: Invalid 32bit issues when using Conan

Merge pull request zeromq#357 from gummif/gfa/nodiscard-recv

Problem: recv return value should not be ignored

Update version to 4.4.1

Merge pull request zeromq#328 from xiphon/fix-recv-flags-default

Fix 'recv' function 'flags_' argument default value

Merge pull request zeromq#256 from Tulon/radio_dish_support

Add support for RADIO/DISH sockets if draft API is enabled

This is release 4.2.3