* [spotbugs] Fix potential NPE in FileRepository#convertToReftable

* IndexDiff/SubmoduleWalk: make the RepositoryBuilder configurable
* IndexDiff/SubmoduleWalk: handle submodule.<name>.ignore correctly

* Convert target platform to simple POM project

* diff: Add "--staged" as alias to "--cached"

* JGit v4.7.8.201903121755-r

* Atomic file creation: hard-linking may not be allowed

* ReceivePackAdvertiseRefsHookTest: Open TestRepository in try-with-resource
* SubmoduleStatusTest: Open TestRepository in try-with-resource
* UploadPackTest: Open TestRepository in try-with-resource
* PackParserTest: Open TestRepository in try-with-resource
* SmartClientSmartServerTest: Open TestRepository in try-with-resource
* Stop using deprecated methods of RemoteSetUrlCommand/RemoteRemoveCommand
* SmartClientSmartServerTest: Stop using deprecated Repository#hasObject
* DumbClientSmartServerTest: Open TestRepository in try-with-resource
* DumbClientDumbServerTest: Open TestRepository in try-with-resource
* DirCacheCheckoutTest: Open TestRepository in try-with-resource
* HttpTestCase#fsck: Open TestRepository in try-with-resource

* Merge branch 'stable-5.1' into stable-5.2

* Use the same default diff.renameLimit = 400 like native git

* InfoRefsServlet: Refactor to not use deprecated methods
* RefAdvertiser: Add send(Collection<Ref>) and deprecate send(Map<String, Ref>)

* Remove package import for javax.servlet.http from org.eclipse.jgit
* Add missing @since tag and silence API error

* Fix javadoc in org.eclipse.jgit nls and notes package
* Fix javadoc in org.eclipse.jgit merge package

* Fix javadoc in org.eclipse.jgit dfs package

* Add photon target platform jgit-4.8.target

* RefSpecs: allow construction of weird wildcarded RefSpecs
* RefSpec: reject refs ending in '/'

* debug-rebuild-ref-tree: Copy HEAD into RefTree
* debug-rebuild-ref-tree: Add --enable flag to turn the database on
* RefTreeDatabase: Allow ORIG_HEAD, etc. on non-bare repositories
* RefTreeDatabase: Expose bootstrap refs in getAdditionalRefs

* Show submodule difference as a hunk

* containsGitModulesFile() should not crash on bare repository

* Update to Jetty 9.2.10

* Prevent NPE if ref can't be resolved when executing ReflogCommand

* Add constructors that take Throwable to ServiceMayNotContinueException.

* DirCacheEditor: Apply PathEdit for each stage

* Fix compile error (method not available in 1.5)

* Create parent dir if necessary on checkout

* Allow to write tests with CLI syntax