Update runtime files.
https://github.com/vim/vim/commit/4f4d51a942cc2c6b3e936ee0f93f00c2d000065c

Omit "??" operator.
Patches v8.2.1794,v8.2.1798 are not ported yet.

Problem:    Cannot cleanup before loading another colorscheme.
Solution:   Add the ColorSchemePre autocommand event.
https://github.com/vim/vim/commit/60a68362aa73f4a6cb534688978f9dc2b16e60fe

Problem:    Color scheme check script shows up as color scheme.
Solution:   Move it to the "tools" subdirectory. (closes vim/vim#2457)
https://github.com/vim/vim/commit/8ee2d36e216756e712a3a9122ce1e1203378a9c8

Problem:    It is not easy to see if a colorscheme is well written.
Solution:   Add a script that checks for common mistakes. (Christian Brabandt)
https://github.com/vim/vim/commit/200d0e36bc5384beb9dc76ac75806ac0aecf84ac

Runtime file updates.

https://github.com/vim/vim/commit/b4ada79aa7d0d1e5da3a659b1a203d7cae9f7f59

Closes #5055

Updated runtime files.

https://github.com/vim/vim/commit/dc08328821a2c11e33dfb1980332e4923ec64fca

NA patches:
vim-patch:8.0.0028
vim-patch:8.0.0029
vim-patch:8.0.0030

Updated runtime files.

https://github.com/vim/vim/commit/64d8e25bf6efe5f18b032563521c3ce278c316ab

Closes #6611

Nvim hasn't ever had X11 integration, so this has was never needed.

Vim runtime files based on 7.4.384 / hg changeset 7090d7f160f7

Excluding:
  Amiga icons (*.info, icons/)
  doc/hangulin.txt
  tutor/
  spell/
  lang/ (only used for menu translations)
  macros/maze/, macros/hanoi/, macros/life/, macros/urm/
      These were used to test vi compatibility.
  termcap
      "Demonstration of a termcap file (for the Amiga and Archimedes)"

Helped-by: Rich Wareham <rjw57@cam.ac.uk>
Helped-by: John <john.schmidt.h@gmail.com>
Helped-by: Yann <yann@yann-salaun.com>
Helped-by: Christophe Badoit <c.badoit@lesiteimmo.com>
Helped-by: drasill <github@tof2k.com>
Helped-by: Tae Sandoval Murgan <taecilla@gmail.com>
Helped-by: Lowe Thiderman <lowe.thiderman@gmail.com>