[build] Default behavior is to skip the Xtend compiler; activate it with -PcompileXtend=true

Jenkinsfile

@@ -10,7 +10,7 @@ node {
 		
 		stage 'Gradle Build'
 		try {
-			sh "./gradlew -PuseJenkinsSnapshots=true clean build createLocalMavenRepo --refresh-dependencies --continue"
+			sh "./gradlew clean build createLocalMavenRepo -PuseJenkinsSnapshots=true -PcompileXtend=true --refresh-dependencies --continue"
 		} finally {
 			step([$class: 'JUnitResultArchiver', testResults: '**/build/test-results/test/*.xml'])
 		}

build.gradle

@@ -25,7 +25,7 @@ subprojects {
 	version = rootProject.version
 	
 	apply plugin: 'java'
-	if (findProperty('skipXtendCompiler') != 'true') {
+	if (findProperty('compileXtend') == 'true') {
 		apply plugin: 'org.xtext.xtend'
 	}
 	apply plugin: 'eclipse'

gradle/eclipse-project-layout.gradle

@@ -16,10 +16,10 @@ sourceSets {
 			srcDirs = sourceDirs
 			exclude '**/*.java', '**/*.xtend'
 		}
-		if (findProperty('skipXtendCompiler') == 'true') {
-			java.srcDir 'xtend-gen'
-		} else {
+		if (findProperty('compileXtend') == 'true') {
 			xtendOutputDir = 'xtend-gen'
+		} else {
+			java.srcDir 'xtend-gen'
 		}
 	}
 	configure(isTestProject? main : test) {

gradle/xtend-compiler-settings.gradle

@@ -2,7 +2,7 @@
  * Configuration of Xtend compiler.
  */
 
-if (findProperty('skipXtendCompiler') != 'true') {
+if (findProperty('compileXtend') == 'true') {
 	[generateXtext, generateTestXtext].each { gen ->
 		gen.xtextClasspath = rootProject.configurations.getByName('xtendCompiler')
 	}