4.0.0: Application initialization & tracing

• Heads up: Removed deprecated transfer() methods from Stream,
  Upload and Response classes, they have been superseded by transmit().
  (@thekid)
• Merged PR #91: Application initialization. Implementations can chose
  to implement the initialize() method (which is empty by default)
  to perform database migration, wait for dependant services, etcetera,
  when the server starts up.
  (@thekid)
• Merged PR #103: Make it possible to append trace data to the response
  which will appear in the log file
  (@thekid)
• Merged PR #102: Extract static content handling into reusable class.
  See also xp-forge/frontend#39
  (@thekid)
• Merged PR #89: Add optional parameter $append to cookie() - @thekid
• Merged PR #107: Fix SAPI uploads with array parameters - @thekid

3.12.0: Export environment variables

• Merged PR #93: Allow passing or removing environment variables via the
  new Environment::export() method
  (@thekid)
• Fixed code not to yield output streams, the AsyncServer API does not
  expect any value there, but it might, see xp-framework/networking#28
  (@thekid)

3.11.0: Flush response

• Ensured the output stream is always closed when it goes out of scope
  (@thekid)
• Removed superfluous layer of output buffering in development webserver
  (@thekid)
• Merged PR #105: Implement WriteChunks::flush() to use for explicitely
  flushing
  (@thekid)

3.10.0: Command line shortcuts

• Merged PR #104: Make xp web [name] load the class xp.[name].Web
  (@thekid)
• Allow -m dev as a shorthand for -m develop following the principle
  "be liberal in what you accept"
  (@thekid)

3.9.0: Error message improvement

• Improve error messages when class reference given on the command line
  is not a web.Application subclass
  (@thekid)
• Added PHP 8.4 to the test matrix - @thekid

3.8.1: EOF handling fix

• Extended EOF handling inside server protocol handler to include NULL,
  preventing warnings inside header reading
  (@thekid)

3.8.0: Header limits

• Merged PR #101: Limit request size (status line and headers) to 16 K.
  This prevents potential out-of-memory scenarios when too many parallel
  requests transmit huge lists of headers slowly. See issue #100 for the
  motivation and how other server implementations handle this
  (@thekid)
• Merged PR #99: Migrate to new testing library - @thekid

3.7.0: Graceful I/O write error handling

• Merged PR #98: Catch socket I/O errors and log them in a less-verbose
  manner (as this is not a server-side issue). See also #97
  (@thekid)

3.6.0: Optional properties

• Merged PR #96: Add ability to check for non-existant properties without
  using exceptions
  (@thekid)

3.5.0: Async uploads

• Merged PR #92: File upload transmission. Using yield from transmit()
  instead of transfer() on file uploads, these can be streamed in an
  asynchronous manner and without blocking other requests.
  (@thekid)