Remove Velocity support

Issue: SPR-13795

Author: jhoeller

spring-context-support/src/main/java/org/springframework/mail/MailPreparationException.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 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.
@@ -18,11 +18,10 @@
 
 /**
  * Exception to be thrown by user code if a mail cannot be prepared properly,
- * for example when a Velocity template cannot be rendered for the mail text.
+ * for example when a FreeMarker template cannot be rendered for the mail text.
  *
  * @author Juergen Hoeller
  * @since 1.1
- * @see org.springframework.ui.velocity.VelocityEngineUtils#mergeTemplateIntoString
  * @see org.springframework.ui.freemarker.FreeMarkerTemplateUtils#processTemplateIntoString
  */
 @SuppressWarnings("serial")

spring-context-support/src/main/java/org/springframework/mail/javamail/MimeMessagePreparator.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 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.
@@ -46,7 +46,7 @@ public interface MimeMessagePreparator {
 	 * @throws java.io.IOException passing any exceptions thrown by MimeMessage methods
 	 * through for automatic conversion to the MailException hierarchy
 	 * @throws Exception if mail preparation failed, for example when a
-	 * Velocity template cannot be rendered for the mail text
+	 * FreeMarker template cannot be rendered for the mail text
 	 */
 	void prepare(MimeMessage mimeMessage) throws Exception;