myplc-5.3-5

Setting tag myplc-5.3-5
last version suitable for f27/f29 with python2
packaging is split up, one more rpm named 'myplc-core' is produced,
that covers the infrastructure side only (without bootcds and nodeimages and all node-oriented material)
no more init file, one systemd service only, that leverages new /usr/bin/plc-ctl
more robust config for httpd and php-fpm and php