Remove unused dependencies

Intended to be a sub-issue of #1041
Initially I'll run https://github.com/nebula-plugins/gradle-lint-plugin/wiki on the project.
Seems I'll also need to make PR:s on the other rptools projects maptool depends on. I won't make issues for those, just reference this issue in those PR:s. (I know I'm in a minority, but, well, I *like* monorepos. I'm lazy. :)