ForgeWrapper

Allow MultiMC to launch Minecraft 1.13+ with Forge.

ForgeWrapper has been adopted by MultiMC, you do not need to perform the following steps manually. (2020-03-29)

For other launchers

ForgeWrapper provides some java properties since 1.4.2:
- forgewrapper.librariesDir : a path to libraries folder (e.g. -Dforgewrapper.librariesDir=/home/xxx/.minecraft/libraries)
- forgewrapper.installer : a path to forge installer (e.g. -Dforgewrapper.installer=/home/xxx/forge-1.14.4-28.2.0-installer.jar)
- forgewrapper.minecraft : a path to the vanilla minecraft jar (e.g. -Dforgewrapper.minecraft=/home/xxx/.minecraft/versions/1.14.4/1.14.4.jar)
ForgeWrapper also provides an interface IFileDetector, you can implement it and custom your own detecting rules. To load it, you should make another jar which contains META-INF/services/io.github.zekerzhayard.forgewrapper.installer.detector.IFileDetector within the full implementation class name and add the jar to class path.

Download Forge installer for Minecraft 1.13+ here.
Download ForgeWrapper jar file at the release page.
Since ForgeWrapper 1.5.1, it no longer includes the json converter, so you need to build it by yourself:
- Download ForgeWrapper sources.
- Extract the zip and open terminal in the extracted folder.
- Run ./gradlew converter:build command in terminal and get the jar from ./converter/build/libs
Run the below command in terminal:
```
java -jar <ForgeWrapper.jar> --installer=<forge-installer.jar> [--instance=<instance-path>]
```
Notice: If you don't specify a MultiMC instance path, ForgeWrapper will create the instance folder in current working space.
If the instance folder which just created is not in MultiMC/instances folder, you just need to move to the MultiMC/instances folder.
Run MultiMC, and you will see a new instance named forge-<mcVersion>-<forgeVersion>.