It was originally resolved by following the symbolic links to determine
the location of the startup script. Mostly adjusted for Debian
distributions and derivatives that have support for "alternatives".
This doesn't work for distributions that install TDE under a
self-contained directory (distros like Dragora, Guix or simply users
that use Graft or GNU Stow tools). Also projects like GSRC...
This code has been improved to cover these cases, also minimizing the
compatibility impact for the readlink command (non-standard) by
eliminating the use of options for greater compatibility, as some systems
do not have the -e or -f options, as they may also have different behavior
Signed-off-by: Matías Fonzo <firstname.lastname@example.org>