Merge branch 'master' into next

Merge branch 'master' into next

* master: (34 commits)
  Remove texts which were added by mistake in 00386272
  Fix formatting which was broken in 00386272
  LockFile: create OutputStream only when needed
  Add a cgit interoperability test for LockFile
  Add TemporaryBuffer.toString(int limit)
  LockFile: create OutputStream only when needed
  Prepare 5.12.0-SNAPSHOT builds
  JGit v5.12.0.202105051250-m2
  Update jetty to 9.4.40.v20210413
  [releng] Update eclipse-jarsigner-plugin to 1.3.1
  Implement ours/theirs content conflict resolution
  ssh: ensure list is modifiable before using Iterator.remove().
  Update orbit to S20210406213021 and add 4.20-staging target
  Fix typo in test method name
  Allow file mode conflicts in virtual base commit on recursive merge.
  sshd: don't lock the known_hosts files on reading
  Allow info messages in UsernamePasswordCredentialsProvider
  ssh config: do environment variable replacement
  sshd: implement server-sig-algs SSH extension (client side)
  Upgrade ecj to 3.25.0
  ...

Change-Id: Ibc39a9c4e431d15b67ab4a307241f47a7f3740a9