This involved messing with both of our source-built plugins (owners and
oauth).
The main issue seems to have been the desync between Jackson as
requested by different plugins. Jackson is split into multiple Maven
packages, and they all have to be the same version to work together. The
oauth plugin was requesting only part of it, and these parts were
incompatible with the parts that the owners plugin requested.
In addition, we have to make the owners plugin include more bits of
Jackson.
Without these changes, we would get runtime
`java.lang.NoClassDefFoundError: com/fasterxml/jackson/...` errors,
which were a symptom of Jackson either not being included fully into the
plugin's JAR, or a mixup between Jackson component/package versions.
While we're at it, we remove the broken theming attempt.
Change-Id: I26531818a395de2a8bb6054d2583881fd1d5b806
Reviewed-on: https://gerrit.hackerspace.pl/c/hscloud/+/1642
Reviewed-by: q3k <q3k@hackerspace.pl>
