Update changelogs.

Author: nedtwigg

CHANGES.md

@@ -14,6 +14,7 @@ We adhere to the [keepachangelog](https://keepachangelog.com/en/1.0.0/) format (
 * `LineEnding.GIT_ATTRIBUTES` now creates a policy whose serialized state can be relocated from one machine to another.  No user-visible change, but paves the way for remote build cache support in Gradle. ([#621](https://github.com/diffplug/spotless/pull/621))
 ### Added
 * `prettier` will now autodetect the parser (and formatter) to use based on the filename, unless you override this using `config` or `configFile` with the option `parser` or `filepath`. ([#620](https://github.com/diffplug/spotless/pull/620))
+* `GitRatchet` now lives in `lib-extra`, and is shared across `plugin-gradle` and `plugin-maven` ([#626](https://github.com/diffplug/spotless/pull/626)).
 ### Changed
 * **BREAKING** `FileSignature` can no longer sign folders, only files.  Signatures are now based only on filename (not path), size, and a content hash.  It throws an error if a signature is attempted on a folder or on multiple files with different paths but the same filename - it never breaks silently.  This change does not break any of Spotless' internal logic, so it is unlikely to affect any of Spotless' consumers either. ([#571](https://github.com/diffplug/spotless/pull/571))
   * This change allows the maven plugin to cache classloaders across subprojects when loading config resources from the classpath (fixes [#559](https://github.com/diffplug/spotless/issues/559)).

plugin-gradle/CHANGES.md

@@ -10,6 +10,7 @@ We adhere to the [keepachangelog](https://keepachangelog.com/en/1.0.0/) format (
 * `prettier` will now autodetect the parser (and formatter) to use based on the filename, unless you override this using `config()` or `configFile()` with the option `parser` or `filepath`. ([#620](https://github.com/diffplug/spotless/pull/620))
 ### Fixed
 * LineEndings.GIT_ATTRIBUTES is now a bit more efficient, and paves the way for remote build cache support in Gradle. ([#621](https://github.com/diffplug/spotless/pull/621))
+* `ratchetFrom` now ratchets from the merge base of `HEAD` and the specified branch.  This fixes the surprising behavior when a remote branch advanced ([#631](https://github.com/diffplug/spotless/pull/631) fixes [#627](https://github.com/diffplug/spotless/issues/627)).
 
 ## [4.4.0] - 2020-06-19
 ### Added