Compatibility with JSG + Update build.gradle

[jhammerberg]

Added compatibility with Just Stargate Mod. Allows for the movement of the Stargate multiblock without breaking any functionality. Also rotates the DHD properly.

I also fixed some URLs not resolving in the build.gradle and made the development instructions more clear in the README.md

[jhammerberg]

90% of this is now redundant because JSG just made a new release that reforms the multiblock when a ship jumps. The Stargate state check is still helpful in preventing a crash.

[jhammerberg]

Apologies for the unnecessary changes, this was my first time doing a pull request and Java development and I didn't know how to only include the pertinent changed files. The changes are still necessary, although the new version of JSG reassembles the multiblock when jumped, it doesn't take into account rotation still which this compatibility module does.

[LemADEC]

You can push new commits that revert the unnecessary changes and, eventually, squash them with git to remove all traces of that temporary blip. In the end, we only want the good working code, we don't care about intermediary development bugs or whatnot.

[jhammerberg]

I've made the requested changes.