Add changelog for VS 2015 Update 1

Author: dungpa

CHANGELOG.md

@@ -9,6 +9,28 @@ Visual F<span>#</span>
 
 All notable changes to this project will be documented in this file.
 
+### [4.0.0] - Visual Studio 2015 Update 1 - 30 November 2015
+
+#### Enhancements
+* Perf: 'for i in expr do body' optimization [#219](https://github.com/Microsoft/visualfsharp/pull/219)
+* Remove type provider security dialog and use custom icon for type provider assembly reference [#448](https://github.com/Microsoft/visualfsharp/pull/448)
+* Perf: Enable parallel build inside Visual Studio [#487](https://github.com/Microsoft/visualfsharp/pull/487)
+* Perf: Remove StructBox for Value Types [#549](https://github.com/Microsoft/visualfsharp/pull/549)
+* Add compiler warnings for redundant arguments in raise/failwith/failwithf/nullArg/invalidOp/invalidArg [#630](https://github.com/Microsoft/visualfsharp/pull/630)
+* Add a compiler warning for lower case literals in patterns [#666](https://github.com/Microsoft/visualfsharp/pull/666)
+
+#### Bug fixes
+* Scope of types for named values in attributes was improperly set [#437](https://github.com/Microsoft/visualfsharp/pull/437)
+* Add general check for escaping typars to check phase [#442](https://github.com/Microsoft/visualfsharp/pull/442)
+* Fix AccessViolationException on obfuscated assemblies [#519](https://github.com/Microsoft/visualfsharp/pull/519)
+* Fix memory leaks while reloading solutions in Visual Studio [#591](https://github.com/Microsoft/visualfsharp/pull/591)
+* Enable breakpoints in 'with' augmentations for class types [#608](https://github.com/Microsoft/visualfsharp/pull/608)
+* Fix false escaping type parameter check error [#613](https://github.com/Microsoft/visualfsharp/pull/613)
+* Fix quotation of readonly fields [#622](https://github.com/Microsoft/visualfsharp/pull/622)
+* Keep the reference icons when opening references [#623](https://github.com/Microsoft/visualfsharp/pull/623)
+* Don't suppress missing FSI transitive references [#626](https://github.com/Microsoft/visualfsharp/pull/626)
+* Make Seq.cast's non-generic and generic IEnumerable implementations equivalent [#651](https://github.com/Microsoft/visualfsharp/pull/651)
+
 ### [4.0.0] - 20 July 2015
 
 Includes commits up to `dd8252eb8d20aaedf7b1c7576cd2a8a82d24f587`