chore[facade]: use picocli for processing command line options

facades/PC/build.gradle

@@ -1,18 +1,5 @@
-/*
- * Copyright 2020 MovingBlocks
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     https://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
+// Copyright 2020 The Terasology Foundation
+// SPDX-License-Identifier: Apache-2.0
 
 // The PC facade is responsible for the primary distribution - a plain Java application runnable on PCs
 
@@ -95,6 +82,9 @@ println "PC VERSION: $version"
 group = 'org.terasology.facades'
 
 dependencies {
+    implementation 'info.picocli:picocli:4.5.1'
+    annotationProcessor 'info.picocli:picocli-codegen:4.5.1'
+
     implementation project(':engine')
     implementation group: 'org.reflections', name: 'reflections', version: '0.9.10'
 
@@ -121,6 +111,11 @@ configurations {
     }
 }
 
+compileJava {
+    // according to https://picocli.info/#_gradle_2
+    options.compilerArgs += ["-Aproject=${project.group}/${project.name}"]
+}
+
 run {
     description = "Run 'Terasology' to play the game as a standard PC application"
     group = "terasology run"