ZmtLaunchPlugin.groovy: fixed issues when applying plugin to launcher project

src/main/groovy/de/zmt/gradle/ZmtLaunchPlugin.groovy

@@ -35,17 +35,14 @@ public class ZmtLaunchPlugin implements Plugin<Project> {
             }
         }
         
-        // if launcher is not available
-        if (launcherProject == null) {
-            // ... add dependency
-            project.dependencies {
-                runtime 'de.zmt:zmt-launcher:latest.release'
-            }
+        // if this project is the launcher
+        if (project.name == 'zmt-launcher') {
+            // make it an application
+            configure(project, MAKE_APPLICATION)
         }
-        
-        // if launcher project is available and it is not this project
-        if (launcherProject != null && launcherProject != project) {
-            // ... include its distribution
+        // else if the launcher project is present
+        else if (launcherProject != null) {
+            // include distribution contents from that project
             launcherProject.afterEvaluate {
                 project.distributions.main.contents {
                     // include launcher and dependencies without sources
@@ -56,17 +53,32 @@ public class ZmtLaunchPlugin implements Plugin<Project> {
                 }
             }
         }
-        // ... otherwise generate start scripts pointing to launcher
+        // the launcher project is not present
         else {
-            apply plugin: 'application'
-            
-            mainClassName = MAIN_CLASS_NAME
+            // add launcher dependency and make it an application
+            project.dependencies {
+                runtime 'de.zmt:zmt-launcher:latest.release'
+            }
+            configure(project, MAKE_APPLICATION)
+        }
         
+        // make jar executable
         jar {
             manifest {
-                    attributes 'Main-Class': mainClassName
+                attributes 'Main-Class': MAIN_CLASS_NAME
+            }
         }
     }
+    
+    /** 
+     * Applies the application plugin, makes the main class point to launcher
+     * and adds start scripts.
+     */
+    private static final def MAKE_APPLICATION = {
+        apply plugin: 'application'
+            
+        mainClassName = MAIN_CLASS_NAME
+    
         startScripts {
             /* Although launcher does not depend on other simulations, those
              * are needed to be included in the class path to be launched. */
@@ -75,8 +87,6 @@ public class ZmtLaunchPlugin implements Plugin<Project> {
         }
     }
     
-    }
-    
     @Override
     void apply(Project project) {
         project.configure(project, CONFIGURE)