Draft: New "BrightIntense" configuration option

This reverts commit 270d6ea3. 270d6 intended to address a desire expressed in bug 405345 to be able to print bold characters without also getting the "intense" color described in the theme.

The user also wants to be able to access the intense color, but by using ANSI codes 90-97, so simply setting the theme to not have a different intense color is inadequate to fully address that bug. This is an unconventional behavior, and is not described in the Wikipedia article on ANSI color sequences or ECMA-048. The behavior is not present at the standard Linux terminal, xterm, nor xfce4-terminal, version 0.8.9.2 (clean install from Debian unstable as of this writing).

As implemented, the commit being reverted here breaks existing behavior, and is not expressed in, e.g., the ncurses terminfo library.

This new behavior must be controlled by a configuration option, and a more complete solution will follow.

Fixes: 430311