chore: adjust the Gradle-based GooeyCLI setup

* Moves it to a maybe more sensible place in the gradle directory where the wrapper lives, this seems kinda related
* Standardizes the source path so we don't need to explicitly configure it
* Drops the Groovy dependency (in Gradle) down to match what's currently in the Gradle Wrapper (although it would still get fetched and used separately for any sort of GooeyCLI *build* process)

gradle/gooeycli/build.gradle

@@ -0,0 +1,35 @@
+// Copyright 2020 The Terasology Foundation
+// SPDX-License-Identifier: Apache-2.0
+apply plugin: 'groovy'
+
+group 'org.terasology.cli'
+
+repositories {
+    jcenter()
+}
+
+dependencies {
+    compile 'org.codehaus.groovy:groovy-all:2.5.10'
+    compile 'info.picocli:picocli-groovy:4.3.2'
+    compile 'org.fusesource.jansi:jansi:1.18'
+    compile 'org.ajoberstar:grgit:1.9.3'
+}
+
+// Ugly hack to allow Gradle and @Grab to get along. See https://github.com/gradle/gradle/issues/1031 - not sure if worth it?
+compileGroovy {
+    // Create temp file.
+    File temp = File.createTempFile("config", ".groovy");
+
+    // Delete temp file when program exits.
+    temp.deleteOnExit();
+
+    // Write to temp file
+    BufferedWriter out = new BufferedWriter(new FileWriter(temp));
+    out.write("""\
+        withConfig(configuration) {
+            configuration.setDisabledGlobalASTTransformations(['groovy.grape.GrabAnnotationTransformation'] as Set)
+        }
+    """.stripIndent());
+    out.close();
+    groovyOptions.configurationScript = temp
+}

config/cli/groovy/org/terasology/cli/ManagedItem.groovy → gradle/gooeycli/src/main/groovy/org/terasology/cli/ManagedItem.groovy

@@ -3,7 +3,7 @@
 package org.terasology.cli
 @GrabResolver(name = 'jcenter', root = 'http://jcenter.bintray.com/')
 @Grab(group = 'org.ajoberstar', module = 'grgit', version = '1.9.3')
-
+import org.ajoberstar.grgit.Grgit
 
 /**
  * Utility class for dealing with items managed in a developer workspace.

gw

@@ -80,8 +80,7 @@ case "`uname`" in
     ;;
 esac
 
-CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar:$APP_HOME/gradle/wrapper/groovy-wrapper.jar:$APP_HOME/config/cli/groovy
-
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar:$APP_HOME/gradle/wrapper/groovy-wrapper.jar:$APP_HOME/gradle/gooeycli/src/main/groovy
 
 # Determine the Java command to use to start the JVM.
 if [ -n "$JAVA_HOME" ] ; then
@@ -180,6 +179,6 @@ save () {
 APP_ARGS=`save "$@"`
 
 # Collect all arguments for the java command, following the shell quoting and substitution rules
-eval set -- $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GroovyWrapperMain config/cli/groovy/org/terasology/cli/GooeyCLI.groovy "$APP_ARGS"
+eval set -- $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GroovyWrapperMain gradle/gooeycli/src/main/groovy/org/terasology/cli/GooeyCLI.groovy "$APP_ARGS"
 
 exec "$JAVACMD" "$@"

gw.bat

@@ -107,11 +107,11 @@ SET CMD_LINE_ARGS=%CMD_LINE_ARGS:~1%
 
 :execute
 @rem Setup the command line
-set CLASSPATH=%APP_HOME%gradle\wrapper\gradle-wrapper.jar;%APP_HOME%gradle\wrapper\groovy-wrapper.jar;%APP_HOME%config\cli\groovy\;
+set CLASSPATH=%APP_HOME%gradle\wrapper\gradle-wrapper.jar;%APP_HOME%gradle\wrapper\groovy-wrapper.jar;%APP_HOME%gradle\gooeycli\src\main\groovy;
 
 
 @rem Execute Groovy via the Gradle Wrapper
-"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -cp "%CLASSPATH%" org.gradle.wrapper.GroovyWrapperMain config/cli/groovy/org/terasology/cli/GooeyCLI.groovy %CMD_LINE_ARGS%
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -cp "%CLASSPATH%" org.gradle.wrapper.GroovyWrapperMain gradle/gooeycli/src/main/groovy/org/terasology/cli/GooeyCLI.groovy %CMD_LINE_ARGS%
 
 :end
 @rem End local scope for the variables with windows NT shell

settings.gradle

@@ -2,7 +2,7 @@ import groovy.io.FileType
 
 rootProject.name = 'Terasology'
 
-include 'engine', 'engine-tests', 'facades', 'metas', 'libs', 'modules', ':config:cli'
+include 'engine', 'engine-tests', 'facades', 'metas', 'libs', 'modules', ':gradle:gooeycli'
 
 // Handy little snippet found online that'll "fake" having nested settings.gradle files under /modules, /libs, etc
 rootDir.eachDir { possibleSubprojectDir ->