Not all codepoints are valid when combined with a presentation
selector.
This commit ensures that we respect the valid sequences defined
by the current version of unicode (version 14).
refs: #1231
refs: #997
I noticed while reviewing the session recording for https://github.com/wez/wezterm/issues/1102
that wezterm reported:
```
2021-09-04T22:05:46.136Z WARN wezterm_term::terminalstate::performer > unknown unspecified CSI: "58::2::87::61::38m"
2021-09-04T22:05:46.138Z WARN wezterm_term::terminalstate::performer > unknown unspecified CSI: "58::2::87::61::38m"
```
Those extra double-colons aren't valid, and I think they're coming from
this terminfo file, so fix it up!
Make a distinction between default and selected presentation,
and account for that in the cell width.
Add a method to the cell that returns the effective presentation.
refs: https://github.com/wez/wezterm/issues/997
* [terminfo] add smxx/rmxx, purge blink
Testing with WezTerm nightly indicates no blink support
available through the xterm \E[5m, and I didn't see any
support in the code -- purge it. smxx and rmxx, meanwhile,
have been added to indicate support for struck text.
* restore blink
Co-authored-by: Wez Furlong <wez@wezfurlong.org>
You can install this into your $TERMINFO directory (default is
`$HOME/.terminfo`) by running:
`tic -x wezterm.terminfo`
from this data directory.
Once installed, you can set `TERM=wezterm`.
refs: https://github.com/wez/wezterm/issues/415
