12.1.0: Refactor I/O exceptions

• Merged PR #7: Refactor I/O exceptions, dropping XP 10 support in the
  doing. See xp-framework/core#363 for a write-up on the reason behind
  this and the plan to move forward.
  (@thekid)
• Added compatibility with PHP 8.5 and PHP 8.6 by suppressing calls to
  the deprecated xml_parser_free() functionality.
  (@thekid)

12.0.0: PHP 7.4+, Reflection

• Dropped support for PHP 7.0 - 7.3, see xp-framework/rfc#343. Minimum
  required PHP version is now 7.4!
  (@thekid)
• Merged PR #5: Remove deprecated static Marshaller / Unmarshaller usage
  (@thekid)
• Merged PR #4: Refactor to use reflection library, xp-framework/rfc#338
  (@thekid)

11.3.0: XP 12 compatibility

• Made compatible with XP 12 - @thekid

11.2.0: Testing migration, PHP 8.4

• Implemented xp-framework/rfc#344: New testing library - @thekid
• Added PHP 8.4 to the test matrix - @thekid

11.1.0: Object serialization

• Added support for __serialize(), which has superseded __sleep() in
  PHP 7.4+, see https://wiki.php.net/rfc/custom_object_serialization
  (@thekid)

11.0.0: Drop XP 9, add XP 11 compatibility

• Made compatible with XP 11 - @thekid
• Implemented xp-framework/rfc#341, dropping compatibility with XP 9
  (@thekid)

10.0.0: Drop PHP 5 support

• Implemented xp-framework/rfc#334: Drop PHP 5.6:
  . Heads up: Minimum required PHP version now is PHP 7.0.0
  . Rewrote code base, grouping use statements
  . Converted newinstance to anonymous classes
  . Rewrote isset(X) ? X : default to X ?? default
  (@thekid)

9.0.4: Annotation syntax

• Implemented RFC #335: Remove deprecated key/value pair annotation syntax
  (@thekid)

9.0.3: XP10 compatibility

• Made compatible with XP 10 - @thekid

9.0.2: PHP 7.4 compatibility

• Made compatible with PHP 7.4 - refrain using {} for string offsets
  (@thekid)
• Replaced all calls to the deprecated xp::stringOf() to use the method
  from util.Objects.
  (@thekid)