Add the graylog2-es-timestamp-fixup tool.

(cherry picked from commit 1c9740e761174a6a21232a1d0ad0abd4ac4567c5)
Add tags to the built docker images.

(cherry picked from commit 6e70300c67b7f66bbcd3f0e7751000e9dde90b3f)
The newer web interface tarballs do not contain api docs anymore.

(cherry picked from commit 65270d892c8ae431278fa3a32f8bd84a7651a9e3)
Bump version to 0.90.1.
Update checksums due to new release artifacts.