Synopsis:
   $nohighlight(<string>)

Technical:
   This function returns <string> with all highlight characters escaped.
   All ^B, ^V, ^_, ^O, ^C, and ^[ characters will be replaced by an inverse
   of their control character, to remove all highlighting.

Practical:
   This is a very useful function, which has had many forms in scripts for
   a long time. It is especially good to mask out ^C and ANSI color codes
   in order to make for color-free output, or in a public message hook to
   immune yourself from ANSI-bombs that may mess up a terminal.

Returns:
   <string> with no parseable highlight characters, except the reverse used
   to show the control character.

Examples:
   $nohighlight(this is a test)           Returns "this BisB a VtestV"

See Also:
   stripansi(6); tr(6)