Firebird - status update

Currently there are two patches I work on.

Update to Firebird 3.0:
https://gerrit.libreoffice.org/25673/

- It seems to be ready for GNU/Linux.
- The new Firebird version requires tommath, so we had to grant a
bundled libtommath external (patch 7).
- Firebird 3.0 uses (instead of fbembed) two libraries for the
embedded functionality: fbclient and Engine12. By default, fbclient
searches Engine12 in a wrong path (in Firebird install dir). There is
a config option to change this (with-fbplugins), but it cannot be used
with a relative path. So I hardcoded the location with a patch.

tdf#72987 Use Firebird backup format
https://gerrit.libreoffice.org/26188/

- It works only with fb 3.0 (I tried it on fb 2.5 too just for
curiosity, and I had some permission problem which I did not
investigated).
- It does not work on install build yet because of an absolute path in
the code. Discussion is here:
https://lists.freedesktop.org/archives/libreoffice/2016-June/074582.html
- We ship the default security database from workdir to instdir/share,
because the service manager of firebird needs it to make an archive
file.
- In case the odb file contains no archive file, it looks for a .fdb
(not archived) database file. When the user saves, it will replace it
with an archive file. It actually fails by now.

regards,
Tamás Bunth