Add Rallly self-hosted scheduling app, simplify CC-BY-SA management (only link to the most recent license version)
Remaining TODO items at #983 (move CC-BY-NC* projects to non-free.md)
@ -230,6 +230,7 @@ Some [Groupware](#groupware) solutions also feature calendar/address book editin
* [Niltalk](http://niltalk.com/) - A simple, private, persistence-free web based multi-room chat server + client. ([Source Code](https://github.com/knadh/niltalk)) `AGPLv3``Go`
* [Node-Chat](https://github.com/IgorAntun/node-chat) - A not-so-basic open-source chat with admin features. `MIT``Nodejs`
* [Pushjet](https://pushjet.io/) - A self hosted push notification service built with a simple API making sending notifications easy. ([Source Code](https://github.com/Pushjet/Pushjet-Server-Api)) `BSD``Python`
* [Rallly](http://rallly.co) - Rallly is a free collaborative scheduling service. ([Source Code](https://github.com/lukevella/Rallly)) `CCBYSA``Nodejs`
* [RetroShare](http://retroshare.org) - Secured and decentralized communication system. Offers decentralized chat, forums, messaging, file transfer. ([Source Code](https://github.com/RetroShare/RetroShare)) `GPLv2``С++`
* [Ring](https://ring.cx/) - Free software for universal communication which respects freedoms and privacy of its users. ([Source Code](https://github.com/savoirfairelinux/ring-project)) `GPLv3``C++`
* [Rocket.Chat](https://rocket.chat/) - Teamchat solution similar to Gitter.im or Slack. ([Source Code](https://github.com/RocketChat/Rocket.Chat)) `MIT``Nodejs`
@ -1206,11 +1207,7 @@ See also [Documentation Generators](#documentation-generators), [Wikimatrix](htt