Release version 0.8.7

Minor release includes support for Ubuntu 22.04

New features:

• Add config options to disable Basic Auth/OAuth1.0a (#262)

Refactoring:

• With the change to C++17, a number of boost libraries and functions have been replaced by their std:: counterparts.
• Added a dependency on the fmt library to ease a future transition from boost::format to std::format (C++20).
• The (cross request-) changeset cache has been removed. This reduces the number of open database connections by one.

Detailed list:

• Adjustments for Ubuntu 22.04 (#255)
• Reduce usage of shared_ptr (#256)
• More code simplifications (#257)
• Some more cleanup (#258)
• More shared_ptr cleanups (#259)
• Migrate boost::variant to std::variant (#260)
• Replace custom array parser by pqxx::array_parser (#261)
• More boost cleanups (#263)
• Move pqxx util functions away from libcgimap_core.so (#264)
• Replace ostringstream formatting by fmt (#265)
• Remove changeset cache (#266)
• Cleanup autotools (#267)
• Update autotools m4 (#269)
• Adding a few more test cases (#270)
• Fix copy&paste error (#272)
• Init some member vars (#273)
• Added new configure option --enable-fmt-header (#274)

Breaking changes:

• Remove Vagrant (#271)
• Parameter --cachesize has been removed as part of #266
• Added a dependency on the fmt library