Update change log and READMe for v4.0.1

Author: tomxor

CHANGELOG.md

@@ -2,8 +2,11 @@
 All notable changes to this project will be documented in this file.
 This project adheres to [Semantic Versioning](http://semver.org/).
 
-## Version [4.0.1][unreleased] - (in development)
-- TBA
+## Version [4.0.2][unreleased] - (in development)
+- TBA.
+
+## Version [4.0.1] - (2015-07-20)
+- Fixed: NPE when processing entries with null links.
 
 ## Version [4.0.0] - (2015-07-20)
 - Changed: `CDAResource` +`Serializable`
@@ -94,7 +97,8 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 ## Version 1.0.0 - 2014-08-13
 Initial release.
 
-[unreleased]: https://github.com/contentful/contentful.java/compare/java-sdk-4.0.0...HEAD
+[unreleased]: https://github.com/contentful/contentful.java/compare/java-sdk-4.0.1...HEAD
+[4.0.1]: https://github.com/contentful/contentful.java/compare/java-sdk-4.0.0...java-sdk-4.0.1
 [4.0.0]: https://github.com/contentful/contentful.java/compare/java-sdk-3.0.0...java-sdk-4.0.0
 [3.0.0]: https://github.com/contentful/contentful.java/compare/java-sdk-2.0.4...java-sdk-3.0.0
 [2.0.4]: https://github.com/contentful/contentful.java/compare/2.0.3...java-sdk-2.0.4

README.md

@@ -15,12 +15,12 @@ Grab via Maven:
 <dependency>
   <groupId>com.contentful.java</groupId>
   <artifactId>java-sdk</artifactId>
-  <version>4.0.0</version>
+  <version>4.0.1</version>
 </dependency>
 ```
 or Gradle:
 ```groovy
-compile 'com.contentful.java:java-sdk:4.0.0'
+compile 'com.contentful.java:java-sdk:4.0.1'
 ```
 
 Snapshots of the development version are available in [Sonatype's `snapshots` repository][snap].
@@ -125,7 +125,7 @@ Copyright (c) 2015 Contentful GmbH. See [LICENSE.txt][6] for further details.
 
 
  [1]: https://www.contentful.com
- [2]: https://oss.sonatype.org/service/local/repositories/releases/content/com/contentful/java/java-sdk/4.0.0/java-sdk-4.0.0.jar
+ [2]: https://oss.sonatype.org/service/local/repositories/releases/content/com/contentful/java/java-sdk/4.0.1/java-sdk-4.0.1.jar
  [3]: https://contentful.github.io/contentful.java/
  [4]: https://www.contentful.com/developers/documentation/content-delivery-api/
  [5]: https://square.github.io/okhttp/