Encourage development with a config system

webmw is currently hardcoded for use in a sucs environment so it's not easy to get it running in a local test environment. It would be a good idea to obtain certain addresses and paths from a config file that isn't overwritten by reinstallation.

Things I've bumped into that should be configurable:

• LDAP connect URL (php/startup.php)
• Various hardcoded URLs in src/mixins/ and src/components/ (https://chat.sucs.org...)
• Whether to force https (php/index.php)
• Location of hackergotchis (path in php/send.php, URLs in src/components/online.vue and src/mixins/mw-sync.js)