$conf['newuser_default_enabled_high'] during user infos creation. Useless
use of boolean_to_string on $conf['newcat_default_status'] was removed.
modification: loading configuration parameter from database was moved to a
dedicated function to be called from include/common.inc.php and from
install.php.
improvement: use of clean insert function during install.
bug fixed: during user information creation, support new status
webmaster/normal/guest instead of admin/guest.
bug fixed: during install, no need to insert obsolete mail_webmaster
configuration parameter.
git-svn-id: http://piwigo.org/svn/branches/branch-1_6@1282 68402e56-0260-453c-a942-63ccdbb3a9ee