This adds support for blinking the terminal cursor. This can be
controlled either using the configuration file, or using escape
sequences.
The supported control sequences for changing the blinking state are
`CSI Ps SP q` and private mode 12.
Teach Alacritty to stop setting the window as urgent upon a bell by
emulating xterm's 'bellIsUrgent' resource and relevant CSI. When this
resource is enabled (with 'CSI ? 1042 h'), a bell event causes the
window to be marked as urgent. When the resource is disabled (with 'CSI
? 1042 l'), the window is not marked urgent in the event of a bell.
There are two wrinkles worth noting here:
- The 'TermMode::URGENCY_HINTS' does _not_ affect the terminal's
configured bell command, since we only want to control whether or
not the window is marked as urgent, not anything else.
- In xterm, the 'bellIsUrgent' resource is _disabled_ by default.
Since bouncing the dock icon has been the default in Alacritty on
macOS thus far, do not make an effort to change that in this patch.
This allows users to emit "\e[?1042l" and disable bouncing the dock
icon.
Fixes#2950.
This adds support for the secondary DA escape sequence response.
Alacritty's version is formatted allowing for up to 99 minor and patch
versions, which should be sufficient.
The tertiary DA is intentionally not implemented and marked as rejected
in the documentation, since a lot of terminals do not support it, or
report useless data (XTerm/URxvt/Kitty).
Fixes#3100.
