Configure the tty driver to ignore the lnext (\cV) and werase (\cW) characters
so they can be bound to fish functions.
Correct the `fish_key_bindings` program to initialize the tty in the same
manner as the `fish` program.
Fixes#3064
I've run this more than twenty times through Travis CI (by adding/removing
a comment line). Without this tweak the longest sequence seems to be
around six successful runs.
This changes the default escape timeout for the default keybindings (emacs
mode) to 300ms and the default for vi keybindings to 10ms.
I couldn't resist fixing a few nits in the fish_vi_key_bindings.fish file
since I was touching it to set the escape timeout.
Introduce a "fish_escape_delay_ms" variable to allow the user to configure the
delay used when seeing a bare escape before assuming no other characters will
be received that might match a bound character sequence. This is primarily
useful for vi mode so that a bare escape character (i.e., keystroke) can
switch to vi "insert" to "normal" mode in a timely fashion.
