RequireThis rule and fixThis Gradle task

* `gradlew clean check -x test --parallel --continue` - to collect reports
* `gradlew fixThis --parallel` - to fix all possible vulnerabilities. With `-Dfile.encoding=UTF-8` on Windows

Since the `RequireThisCheck` doesn't see parents for anonymous classes (e.g. `Runnable` callback), its report doesn't contains the outer class name with `this.`,
therefore we still have to fix those cases manually.
Thanks to the wrong `replacer` just with `this.` we have uncompilable code enough easy to find problems.
Not so easy to fix for good readability though...

* Upgrade to Grade 2.12
* Upgrade to SonarQube native plugin

The fix contains at about 300 files. So, will be done on merge.

Fix `fixThis.gradle` according PR comments

Apply `fixThis` and also `fixModifiers` for test classes.
 Fix some `this.` inner issues manually.
 Make code polishing for long lines after `fixThis`

Fix conflicts and vulnerabilities after the rebase

spring-integration-syslog/src/main/java/org/springframework/integration/syslog/DefaultMessageConverter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2016 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -64,7 +64,7 @@ public class DefaultMessageConverter implements MessageConverter, BeanFactoryAwa
 	}
 
 	protected boolean asMap() {
-		return asMap;
+		return this.asMap;
 	}
 
 	@Override

spring-integration-syslog/src/main/java/org/springframework/integration/syslog/RFC5424SyslogParser.java

@@ -205,7 +205,7 @@ public class RFC5424SyslogParser {
 		private int mark;
 
 		public Reader(String l) {
-			line = l;
+			this.line = l;
 		}
 
 		public void mark() {
@@ -214,23 +214,23 @@ public class RFC5424SyslogParser {
 
 		public String getMarkedSegment() {
 			Assert.state(this.mark <= this.idx, "mark is greater than this.idx");
-			return this.line.substring(mark, this.idx);
+			return this.line.substring(this.mark, this.idx);
 		}
 
 		public int current() {
-			return line.charAt(this.idx);
+			return this.line.charAt(this.idx);
 		}
 
 		public int prev() {
-			return line.charAt(this.idx - 1);
+			return this.line.charAt(this.idx - 1);
 		}
 
 		public int getc() {
-			return line.charAt(this.idx++);
+			return this.line.charAt(this.idx++);
 		}
 
 		public int peek() {
-			return line.charAt(this.idx + 1);
+			return this.line.charAt(this.idx + 1);
 		}
 
 		public void ungetc() {
@@ -271,19 +271,19 @@ public class RFC5424SyslogParser {
 		}
 
 		public boolean is(char c) {
-			return line.charAt(this.idx) == c;
+			return this.line.charAt(this.idx) == c;
 		}
 
 		public boolean was(char c) {
-			return line.charAt(this.idx - 1) == c;
+			return this.line.charAt(this.idx - 1) == c;
 		}
 
 		public boolean isDigit() {
-			return Character.isDigit(line.charAt(this.idx));
+			return Character.isDigit(this.line.charAt(this.idx));
 		}
 
 		public void expect(char c) {
-			if (line.charAt(this.idx++) != c) {
+			if (this.line.charAt(this.idx++) != c) {
 				throw new IllegalStateException("Expected '" + c + "' @" + this.idx);
 			}
 		}
@@ -296,7 +296,7 @@ public class RFC5424SyslogParser {
 		}
 
 		public String rest() {
-			return line.substring(this.idx);
+			return this.line.substring(this.idx);
 		}
 
 		public String getIdentifier() {
@@ -346,11 +346,11 @@ public class RFC5424SyslogParser {
 		}
 
 		public int level() {
-			return level;
+			return this.level;
 		}
 
 		public String label() {
-			return label;
+			return this.label;
 		}
 
 		public static Severity parseInt(int syslogSeverity) {

spring-integration-syslog/src/main/java/org/springframework/integration/syslog/inbound/RFC6587SyslogDeserializer.java

@@ -97,7 +97,7 @@ public class RFC6587SyslogDeserializer implements Deserializer<Map<String, ?>> {
 		else {
 			throw new IllegalStateException("Expected a digit or '<', got 0x" + Integer.toHexString(peek));
 		}
-		return parser.parse(line, octetCount, shortRead);
+		return this.parser.parse(line, octetCount, shortRead);
 	}
 
 	private boolean isDigit(int peek) {

spring-integration-syslog/src/main/java/org/springframework/integration/syslog/inbound/SyslogReceivingChannelAdapterSupport.java

@@ -77,7 +77,7 @@ public abstract class SyslogReceivingChannelAdapterSupport extends MessageProduc
 	@Override
 	protected void onInit() {
 		super.onInit();
-		if (!converterSet) {
+		if (!this.converterSet) {
 			((DefaultMessageConverter) this.converter).setBeanFactory(this.getBeanFactory());
 		}
 	}
@@ -85,8 +85,8 @@ public abstract class SyslogReceivingChannelAdapterSupport extends MessageProduc
 	protected void convertAndSend(Message<?> message) {
 		try {
 			if (message instanceof ErrorMessage) {
-				if (logger.isDebugEnabled()) {
-					logger.debug("Error on syslog socket:" + ((ErrorMessage) message).getPayload().getMessage());
+				if (this.logger.isDebugEnabled()) {
+					this.logger.debug("Error on syslog socket:" + ((ErrorMessage) message).getPayload().getMessage());
 				}
 			}
 			else {