Remove libuv-overlapped.patch since UV_OVERLAPPED_PIPE was included in
libuv v1.21.0:
https://github.com/libuv/libuv/commit/62a0f763a7d1a5bbaa2670b9d2687ba183d2c528

Notable changes since v1.12:
- 1.16.0
  - uv_os_getppid(): get parent PID
  - "win,tty: improve SIGWINCH support" (v1.15.0)
- 1.18.0
  - uv_os_getpid()
- 1.19.0
  - Windows: uv_kill() pid 0 now means "current process group", like unix.
    https://github.com/libuv/libuv/commit/890eedaf59cea75faaa6a14b4248a472dcadb831
- 1.20.0
  - unix,spawn: respect user stdio flags for new pipe
    https://github.com/libuv/libuv/commit/c409b3fcff51ea270724e4f43866764e65666095

In the 20180331 release, the format was slightly changed:

> 20180331
>         + improve terminfo write/read by modifying the fourth item of the
>           extended header to denote the number of valid strings in the extended
>           string table (prompted by a comment in unibilium's sources).

Since the number of valid string capabilities is not necessarily the
same as extstrslen, it's not possible to sanity check the total number
of items up front anymore.

Not needed after libvterm commit:
https://github.com/neovim/libvterm/commit/487f21dbf65f1c28962fef3f064603f415fbaeb2

Only includes the tools needed for Neovim: xgettext, msgfmt, and
msgmerge.

The escape sequence `\e` is non-standard and not supported by MSVC.
It caused the terminal emulator to incorrectly interpret certain keys.

This will be used e.g. by the python client for native asyncio support