Heads up: Tracker to require that sqlite>=3.20.0 is compiled with --enable-fts5

[Carlos Garnacho <carlosg gnome org>]

Hi all,

Sqlite 3.20.0 broke API/ABI for Tracker purposes. The change described
in point 3 at http://sqlite.org/releaselog/3_20_0.html is not only
backwards incompatible, but also brings backwards and forwards
incompatibilities with standalone FTS5 modules like Tracker ships [1],
all of those are only visible at runtime [2].

FTS5 modules generated from SQLite < 3.20.0 won't work with >= 3.20.0,
and the other way around. Since it's not tenable to ship multiple FTS5
module copies for pre/post 3.20.0, Tracker shall now make it a hard
requirement that SQLite is compiled with builtin FTS5 (--enable-fts5)
if SQLite >= 3.20.0 is found. The current Tracker FTS5 module is kept
for older SQLite versions.

This change applies to Tracker >=1.12.3 and >=1.99.3. I don't know if
any distro pushed SQLite 3.20.0 in combination with a Tracker that is
older than that, but it will be just as broken, those would require
additional patches from the tracker-1.12 branch besides the described
change.

Please handle this promptly, wherever there's sqlite 3.20.0 without
builtin FTS5 and/or tracker <= 1.12.2/1.99.2, there's unhappy Tracker
users.

Cheers,
  Carlos

[1] Generated as described in
http://sqlite.org/fts5.html#building_a_loadable_extension
[2] https://bugzilla.gnome.org/show_bug.cgi?id=785883