RemoteTech 1.5.0

~~Except for #193, which still needs to be reviewed,~~ this PR contains all the changes I'd like to release as version 1.5.0. The list is quite lengthy.

Please use [`build-develop-106`](https://github.com/RemoteTechnologiesGroup/RemoteTech/releases/tag/build-develop-106) for playtesting; note that you will have delete the old `RemoteTech2` folder before installing the new `RemoteTech` folder.