(Credit: Zach Wegner, https://github.com/neovim/neovim/pull/11034)

Problem:    "precedes" in 'listchars' not used properly.
Solution:   Correctly handle the "precedes" char in list mode for long lines.
https://github.com/vim/vim/commit/bffba7f7042f6082e75b42484b15f66087b01941

Previously, the "precedes" character would be rendered on every row
when w_skipcol > 0 (i.e., when viewing a single line longer than the
entire screen), instead of just on the first row. Make sure to only
render it on the first row in this case.

Add a test for this behavior.

Fix documentation for the "precedes" character, which erroneously
stated that it was only active when wrap mode was off.

These options were previously global. A global-local window option
behaves closer to a global option "per default" (i e with :set),
but still supports local behavior via :setl

Also this restores back-compat for nvim_set_option("fcs", ...)
which are currently broken on 0.4.x but worked in earlier versions

Vim patch 8.1.0856 (54d9ea6) caused a performance regression in Neovim,
when `set conceallevel=1 nocursorline` was used, since then due to
refactoring in 23c71d5 `w_last_cursorline` would never get updated
anymore.

Adds/uses `redrawdebug+=nodelta` for testing this.

Fixes https://github.com/neovim/neovim/issues/11100.
Closes https://github.com/neovim/neovim/pull/11101.

Given the other type names "jumps", "vars", etc., the name "buflist"
is somewhat unintuitive.

Since the parameter is already non-primitive, make it an `opts` map
instead of just a list, in case we want to extend it later.

fix #8428

fix #3436

Includes:
vim-patch:8.0.1038: strike-through text not supported

"enter"/"leave" is more conventional for Vim events, and
"attach"/"detach" distinction does not gain much.