This avoids having a green (by default) border around the cursor.
The dynamic color escape sequences have been updated to also
change the border color when the cursor background color is changed.
This includes a script to generate a screenshot from a wezterm
running the default config under X11.
It expects the iTerm2-Color-Schemes to be checked out alongside
the wezterm repo as it uses the dynamic color schemes scripts
to activate the schemes one by one and capture the display.
