Merge tag 'v5.2.15' into v5.2/standard/base

This is the 5.2.15 stable release

# gpg: Signature made Mon 16 Sep 2019 02:23:24 AM EDT
# gpg:                using RSA key 647F28654894E3BD457199BE38DBBDC86092693E
# gpg: Can't check signature: No public key