partial merge -r1173:1174 from branch-1_6 to trunk: new configuration
parameter die_on_sql_error (upgrade.php and install/upgrade_*.php not
concerned on BSF)
partial merge -r1208:1209 from branch-1_6 to trunk (only bug fix on
incorrect insertion of complex upgrade identifiers)
deletions: upgrade.php and all install/upgrade_*.php because these script
are never up to date on BSF. Anyway, they are only required on a stable
branch.