Wrapping it will send it to the terminal "directly", which might change the
cursor of another pane, e.g. when starting Neovim and changing to
another pane directly.

tmux has a terminfo extension (Ss/Se) to handle and translate the
DECSCUSR sequences internally.  This can be controlled through
`terminal-overrides`, but does not appear to be able to handle the
uncommon sequences for Konsole.

Two new keys have been added to key_name_entry in keymap.c:
`FocusGained` and `FocusLost`.

Two cases have been added to the key handing switch in edit.c each
applying their respective autocmds.

In normal.c two functions have been added alongside nv_cursorhold doing
a similar job of applying the autocmd for the appropriate key.

tui/input.c has a new function `handle_focus_event` which eats either of
the control sequences for focus gained or lost. This function is checked
before handle_bracketed_paste and handle_forced_escape.

tui.c registers neovim as able to receive these control sequences in
terminfo_start and undoes that in terminfo_stop.

Closes #2302

Fixed by waiting until the UI thread finishes processing events. Close #3541.

Ref: https://github.com/neovim/neovim/issues/3547#issuecomment-152156639

The abort came from using libuv tty handle on non-tty fd. Use uv_pipe_t in these
cases. Also add simple test for this case.

This is required to have <esc> working correctly when the
`ttimeout`/`ttimeoutlen` options are set. Ref:
https://github.com/neovim/neovim/issues/2093#issuecomment-146506480

Closes #3399

Take the return value of input_enqueue into consideration, waiting for the main
thread to consume input. Close #1714 #3377.

Add a new special key that can be used by UIs to toggle the 'paste' option and
use it in the TUI instead of the user's 'pastetoggle' value.

Close #2843 #2092