Add beta.4 changelog (PowerShell#4245)

* first pass at beta.4 changelog

* grammar and spelling fixes (PowerShell#1)

CHANGELOG.md

@@ -1,5 +1,36 @@
 # Changelog
 
+## v6.0.0-beta.4 - 2017-07-12
+
+- Add Windows PowerShell `PSModulePath` by default on Windows. (#4132)
+- Move PowerShell to `2.0.0-preview3-25426-01` and using the .NET CLI version `2.0.0-preview2-006502`. (#4144)
+
+### Engine updates and fixes
+
+- Performance improvement in PSReadline by minimizing writing ANSI escape sequences. (#4110)
+- Implement Unicode escape parsing so that users can use Unicode characters as arguments, strings or variable names. (#3958) (Thanks to @rkeithhill!)
+- Script names or full paths can have commas. (#4136) (Thanks to @TimCurwick!)
+- Added `semver` as a type accelerator for `System.Management.Automation.SemanticVersion`. (#4142) (Thanks to @oising!)
+- Close `eventLogSession` and `EventLogReader` to unlock an ETL log. (#4034) (Thanks to @iSazonov!)
+
+### General cmdlet updates and fixes
+
+- `Move-Item` cmdlet honors `-Include`, `-Exclude`, and `-Filter` parameters. (#3878)
+- Add a parameter to `Get-ChildItem` called `-FollowSymlink` that traverses symlinks on demand, with checks for link loops. (#4020)
+- Change `New-ModuleManifest` encoding to UTF8NoBOM on non-Windows platforms. (#3940)
+- `Get-AuthenticodeSignature` cmdlets can now get file signature timestamp. (#4061)
+- Add tab completion for `Export-Counter` `-FileFormat` parameter. (#3856)
+- Fixed `Import-Module` on non-Windows platforms so that users can import modules with `NestedModules` and `RootModules`. (#4010)
+- Close `FileStream` opened by `Get-FileHash`. (#4175) (Thanks to @rkeithhill!)
+
+### Remoting
+
+- Fixed hang when the SSH client abruptly terminates. (#4123)
+
+### Documentation
+
+- Added recommended settings for VS Code. (#4054) (Thanks to @iSazonov!)
+
 ## v6.0.0-beta.3 - 2017-06-20
 
 ### Breaking changes