Overhauling file system structure.

Common files such as assets, libraries, and mods have been externalized into a 'common' folder. Each server now has its own instance folder to allow saving per version files. This resolves issues with resourcepacks and mod configurations being overriden, and still preserves our optimizations in storing libraries and mods maven style.

app/assets/js/scripts/landing.js

@@ -257,9 +257,10 @@ function asyncSystemScan(launchAfter = true){
 
     // Fork a process to run validations.
     sysAEx = cp.fork(path.join(__dirname, 'assets', 'js', 'assetexec.js'), [
-        ConfigManager.getGameDirectory(),
+        ConfigManager.getCommonDirectory(),
         ConfigManager.getLauncherDirectory(),
-        ConfigManager.getJavaExecutable()
+        ConfigManager.getJavaExecutable(),
+        ConfigManager.getInstanceDirectory()
     ], {
         stdio: 'pipe'
     })
@@ -436,9 +437,10 @@ function dlAsync(login = true){
 
     // Start AssetExec to run validations and downloads in a forked process.
     aEx = cp.fork(path.join(__dirname, 'assets', 'js', 'assetexec.js'), [
-        ConfigManager.getGameDirectory(),
+        ConfigManager.getCommonDirectory(),
         ConfigManager.getLauncherDirectory(),
-        ConfigManager.getJavaExecutable()
+        ConfigManager.getJavaExecutable(),
+        ConfigManager.getInstanceDirectory()
     ], {
         stdio: 'pipe'
     })
@@ -581,7 +583,7 @@ function dlAsync(login = true){
                 //}
                 const authUser = ConfigManager.getSelectedAccount()
                 console.log('authu', authUser)
-                let pb = new ProcessBuilder(ConfigManager.getGameDirectory(), serv, versionData, forgeData, authUser)
+                let pb = new ProcessBuilder(serv, versionData, forgeData, authUser)
                 setLaunchDetails('Launching game..')
                 try {
                     // Build Minecraft process.