quakespasm 0.90.0

Version 0.90.0 of QuakeSpasm is released.
Changes since the previous version:

• Fix issues on Windows systems with DPI scaling.
• Unix/Mac user directories support. Disabled by default,
  'make DO_USERDIRS=1' to enable it.
• SDL2 support. Disabled by default, 'make USE_SDL2=1' to enable it.
• Revised keyboard input code.
• Revised/improved the 'game' command, i.e. on-the-fly mod changing.
  It now accepts an optional second argument for mission packs or
  quoth support i.e. -hipnotic, -rogue, or -quoth. For example, for
  WarpSpasm: "game warp -quoth"
• Command line: "-game {quoth/hipnotic/rogue}" is now treated the
  same as -quoth, -hipnotic, or -rogue.
• Console speed now resolution-independent.
• Disabled gl_zfix, which caused glitches and is undesirable for new
  maps. Replacement .ent files to fix z-fighting for several id1 maps
  added to quakespasm.pak.
• PF_VarString buffer bumped to 1024, avoids truncated centerprints
  from the 'In The Shadows' mod.
• Support for opengl non-power-of-two-textures extension (disable
  with command line: "-notexturenpot".)
• Support for OpenGL vertex buffer objects (VBO, OpenGL 1.5 or newer)
  for world and brush models (disable with command line: "-novbo".)
• Antialiasing (FSAA) support (command line: -fsaa x, where x can be
  0, 2, 4, 8).
• Fence textures support.
• Dynamic light speedup. Speedup loading of tga and pcx external
  images.
• Brush model drawing speedup.
• Support for BSP2 and 2PSB map formats.
• Support for Opus, FLAC, and tracker music (S3M, IT, UMX, etc.), as
  compile-time options.
• Music and sfx now mixed at 44100Hz to avoid downsampling music.
  Low-pass filter applied to the sfx if -sndspeed is 11025 (the
  default), to preserve the same sound quality as 0.85.9. New
  -mixspeed option sets the rate for mixing sfx and music, and output
  to the OS (default 44100), setting it to 11025 reverts to 0.85.9
  behaviour. New snd_filterquality cvar, value can be between 1
  (emulate OS X resampler) and 5 (emulate Windows resampler),
  controls the sound of the low-pass filter.
• Better Hor+ field of view (FOV) scaling behavior.
• Better cross-map demo playback support.
• Fix screenshots when screen width isn't a multiple of 4.
• Fix a lighting glitch due to floating point precision.
• Fix a looping sounds glitch.
• Fix a vulnerability in file extension handling. Tighten path
  handling safety.
• Initialize opengl with 24-bit depth buffer at 32 bpp.
• Reset all models upon gamedir changes. (Fixes failures with mods
  using custom content.)
• Fix broken behavior upon gamedir changes if -basedir is specified
  on the command line.
• NET_MAXMESSAGE and MAX_MSGLEN limits bumped to 64000.
• MAX_EFRAGS bumped to 4096, and MAX_CHANNELS to 1024.
• MAX_ENT_LEAFS bumped from 16 to 32 to work around disappearing or
  flickering brush models in some situations. Also, if an entity is
  visible from MAX_ENT_LEAFS or more leafs, we now always send it to
  the client.
• Fix cvar cycle command not working sometimes.
• Host_Error upon missing models. (Prevents segmentation faults.)
• Change sv_aim default value to 1 (i.e. turn off autoaim)
• Add 'prev' and 'next' keywords to the 'cd' command.
• Work around a linux cdrom issue (playback might not start for a
  while after a stop).
• Quakespasm content customization moved from engine-embedded into a
  new optional quakespasm.pak file.
• Version bumped to 0.90.0 (because Quakespasm has a decent life of
  it's own)
• Other fixes and clean-ups.