12.0.0: PHP 8 semantics

This major release adopts more PHP 8 semantics, getting rid of the XP annotation syntax with @ and deprecating implicitely nullable types. This is the last major release to support PHP 7, and only does so for its newest version.

Heads up!

• Removed deprecated Mersenne Twister algorithm from util.Random, see
  https://wiki.php.net/rfc/deprecations_php_8_3#global_mersenne_twister
  (@thekid)
• Removed the deprecated resolve() method from lang.Process. Use
  lang.CommandLine::resolve() instead!
  (@thekid)
• Removed Proxy and InvocationHandler from the lang.reflect package,
  and AbstractDeferredInvokationHandler from util. See PR #341
  (@thekid)

RFCs

• Implemented xp-framework/rfc#342: Extract compression streams, removing
  the implementing classes from io.streams. See PR #342.
  (@thekid)
• Implemented xp-framework/rfc#336, part 2: Remove XP annotations syntax,
  which was deprecated in XP 11, released October 2021. See PR #340.
  (@thekid)
• Implemented xp-framework/rfc#343, part 1: Drop support for all but the
  latest PHP 7 release. The minimum required PHP version is now 7.4!
  (@thekid)

Features

• Synchronized mime types list with most recent jshttp/mime-db - @thekid
• Merged PR #338: Set default character set for property files to utf-8
  (@thekid)

Bugfixes

• Fixed issue #336: Deprecate implicitly nullable parameter types, following
  https://wiki.php.net/rfc/deprecate-implicitly-nullable-types
  (@thekid)