Open text files with non-editor
Some text files are not meant to be open in a text editor. For example, a .lyx file has a format that is plain text but it is meant to only be edited by the application LyX.

taskopen currently sees "text" in the following output

```
$ file lyxfile.lyx 
lyxfile.lyx: LyX document text
```

and decides to open with EDITOR because of the following code:

```
if ($filetype =~ m/text|empty/ ) {
                $cmd = qq/$EDITOR/;
}
```

On first thought, I think I would prefer to get rid of the hardcoded detection of text files. Why not let `xdg-open` just deal with everything? That way the user can easily customize the behavior from a central location.

Back to this specific issue, it is difficult for me to configure taskopen to open .lyx files in LyX. One solution would be to process the custom regexes before the default regexes. Again on first thought (as you can see, I am hesitant to suggest these changes with confidence), this seems to make sense, because if a custom regex matches, a user likely prefers the custom command over the default command.

I volunteer to make a patch, if we can decide on the desired behavior.
