Hi Francois,
I also thought something like what you said...,
but I took a look to the unpacked files ...
.... there I found some files that look to be able to work good in order to configure firefox...:
- updater.ini
- updater
- precomplete
- removed-files
- platform.ini
- ...............
....
(for example)... the content of the file precomplete is this :
==============================
==
remove "updater.ini"
remove "updater"
remove "run-mozilla.sh"
remove "removed-files"
remove "precomplete"
remove "plugin-container"
remove "platform.ini"
remove "omni.ja"
remove "libxul.so"
remove "libssl3.so"
remove "libsoftokn3.so"
remove "libsoftokn3.chk"
remove "libsmime3.so"
remove "libplds4.so"
remove "libplc4.so"
..............................
,.............................
rmdir "icons/"
rmdir "gtk2/"
rmdir "gmp-clearkey/0.1/"
rmdir "gmp-clearkey/"
rmdir "dictionaries/"
rmdir "defaults/pref/"
..............................
,.............................
===========================
are you sure that simply unpack the files in /usr/local is the best way to arrange the installation ?