use LL::NG::Handler instead of custom perl module in apache config
To protect apps with LL::NG, an administrator has to build his own perl package calling LL::NG::Handler::SharedConf, and executing PACKAGE->init($h), where $h is a parameters hashref. But $h is often empty, since now most parameters are in global conf and in lemonldap-ng.ini.
It would be meaningful to call PACKAGE->init({}) in LL::NG::Handler. Now, LL::NG::Handler is just an alias of LL::NG::Handler::SharedConf, so it is not really useful. Add init() in Handler.pm would make this package directly usable by an administrator, so a basic configuration LL::NG would be easier to set: no custom package anymore, just add "PerlHeaderParserHandler Lemonldap::NG::Handler" in apache config.