Added Fedora 40 support.
Included upgrading ACE requirement to latest stable 7.1.0.
6.3.3 had a stropts compile error.
Added dialog app `fzf`.
Added settings and enabled control from environment.
Propagated database selection control.
Updated and organized, paths and database name(s).
Organized code.

Make choice value shell error code response less error prone with more explicit block control flow with additional keywords.
Add shellcheck exception as that situation was intentional, and even performed successfully in older script versions, as assumed.

Use `installer` variable as I think would be intended to easily utilize the benefit of keeping the other related code portions.

Propagate shellcheck exception to the relevant original code as well.

Per AppVeyor build failure, seems that file is required by the build system, not produced by from it.

for incremental build capability from the install script.