LTS feature deprecation

[totaam]

Things that should be removed or deprecated before or just after the next LTS release:

• remove init.d script? linter complains that E: xpra: init.d-script-not-included-in-package etc/init.d/xpra
• move the numerous xkbmap_PROPERTY values to a keyboard-map dict so we can more easily tidy up keyboard support
• drop old ffmpeg compat code:
  

  xpra/xpra/codecs/dec_avcodec2/register_compat.c

  Lines 10 to 13 in c001342

  	void register_all(void) {
  	#if LIBAVCODEC_VERSION_INT < AV_VERSION_INT(58, 9, 100)
  	av_register_all();
  	#endif

• drop 32-bit builds?
• drop CUDA < 11.5 cruft:
  

  xpra/setup.py

  Line 2092 in c001342

  if nvcc_version>=(11, 5):

• drop old auth syntax: --tcp-auth=, show deprecation warning
• compression_level / set_deflate?
• rencodeplus as only packet encoder - deprecate everything else
• deprecate zlib (encoding.rgb_zlib etc) - lz4 as only compressor for now
• drop mmap non-namedspaced caps
• remove sound.bundle-metadata caps
• drop premult icon format - add webp? (encodings.window-icon : premult_argb32, BGRA, default, png
• assume info-namespace = True
• assume xdg-menu-update = True
• drop invalid csc modes (Alpha for encodings that don't handle alpha ), ie: jpeg : BGRX, BGRA, YUV420P
• assume: encoding.eos = True, encoding.flush = True
• remove tcp_proxy
• consider new packet format: dictionary instead of positional arguments #1942 and untranslated keyboard #1172
• remove fakeXinerama in favour of dummy >= 0.4
• randr_notify
• wants_default_cursor and friends
• simplify RPM spec file (replace python2-*)
• remove python-lz4 fallback: lz4 cython bindings #3601
• can probably remove a lot of strtobytes (ie: 4da5b3b)
• can remove legacy workarounds such as this one:
  

  xpra/xpra/net/file_transfer.py

  Lines 371 to 373 in 59f2456

  	#this is for legacy packet encoders only:
  	if isinstance(file_data, str):
  	file_data = strtobytes(file_data)

[totaam]

As per ff0a3d0, use generic want flags.

[totaam]

See also #3930