Use new xtext gradle plugins. Added some javadoc

Signed-off-by: Dennis Huebner <dennis.huebner@gmail.com>

plugins/org.eclipse.xtext.util/src/org/eclipse/xtext/util/XtextVersion.xtend

@@ -6,16 +6,62 @@ import java.net.URL
 import java.util.jar.Manifest
 import org.eclipse.emf.common.EMFPlugin
 import org.eclipse.xtend.lib.annotations.Data
+
 /**
  * @since 2.9
  */
 @Data
 class XtextVersion {
-	
+
+	String version
+
 	static def getCurrent() {
 		new XtextVersion(readVersionFromManifest ?: 'unknown')
 	}
+
+	def getXtextGradlePluginVersion() {
+		'1.0.2'
+	}
+
+	/**
+	 * @noreference
+	 */
+	def getMweVersion() {
+		'2.8.3'
+	}
+
+	def getXtendGradlePluginVersion() {
+		xtextGradlePluginVersion
+	}
+
+	/**
+	 * @noreference
+	 */
+	def getXtendAndroidGradlePluginVersion() {
+		xtendGradlePluginVersion
+	}
 	
+	/**
+	 * @return <code>true</code> if the current version ends with '-SNAPSHOT'
+	 */
+	def isSnapshot() {
+		version.endsWith("-SNAPSHOT")
+	}
+	
+	/**
+	 * @return <code>true</code> if the current version is not a snapshot and not a release<br>
+	 * 				Release builds must match a following pattern: N.N(.N)+<br>
+	 *  			(N is a digit)<br>
+	 * 				For example 2.9.2 is a release, 2.9.2.beta3 is stable.
+	 */
+	def isStable() {
+		return !isSnapshot && !version.matches("\\d+\\.\\d+(\\.\\d+)+")
+	}
+
+	override toString() {
+		version
+	}
+
 	private static def readVersionFromManifest() {
 		var InputStream is
 		try {
@@ -27,51 +73,23 @@ class XtextVersion {
 			return null;
 		} finally {
 			if (is != null) {
-				try { is.close() }
-				catch (IOException e) {}
+				try {
+					is.close()
+				} catch (IOException e) {
+				}
 			}
 		}
 	}
 
 	private static class Plugin extends EMFPlugin {
 		public static final Plugin INSTANCE = new Plugin
+
 		private new() {
 			super(#[]);
 		}
+
 		override getPluginResourceLocator() {
 		}
 	}
-	
-	String version
-	
-	def isSnapshot() {
-		version.endsWith("-SNAPSHOT")
-	}
-	
-	def isStable() {
-		return !isSnapshot && !version.matches("\\d+\\.\\d+(\\.\\d+)+")
-	}
-	
-	def getXtendGradlePluginVersion() {
-		xtextGradlePluginVersion
-	}
-	
-	def getXtendAndroidGradlePluginVersion() {
-		'0.4.14'
-	}
-	
-	def getXtextGradlePluginVersion() {
-		'1.0.1'
-	}
 
-	/**
-	 * @noreference
-	 */
-	def getMweVersion() {
-		'2.8.3'
-	}
-	
-	override toString() {
-		version
-	}
 }