Replace SQLHeavy with SQLite

We should aslo consider the sqlite classes that geary has developed.

https://git.gnome.org/browse/geary/tree/src/engine/db

After all, they ditched sqlheavy too and - I guess - wanted to write a better component while retaining some compatibility with the sqlheavy API.

Also, they have a Connection abstraction (used to update the database from other threads)

Note that pantheon-photos has its own data access classes: http://bazaar.launchpad.net/~pantheon-photos/pantheon-photos/trunk/files/head:/src/db/

Both of those applications were written by Yorba. Shotwell/Photos classes predate official SQLite bindings, and the same devs did not use them for Geary. Interesting.

Debian has removed sqlheavy from its repos about a month ago, so this may be considered a mild portability blocker now.

Also note that noise is using a pretty old version of sqlite right now.

 Noise uses sqlite 3.8.2 that has been released 2013-12-06.
The new release 3.8.7.1 (2014-10-30) is mostly about performance gain. Not that sqlite is the factor limiting the performance (not anymore) or a major memory user, but any performance boost is appreciable.
Besides sqlite is heavily tested (test coverage is more than 100%) so upgrades are deemed pretty safe.

apt-cache policy sqlite3
sqlite3:
  Installed: (none)
  Candidate: 3.8.2-1ubuntu2
  Version table:
     3.8.2-1ubuntu2 0
        500 http://fr.archive.ubuntu.com/ubuntu/ trusty/main amd64 Packages

(I'm so ignorant of the basic linux software distribution stuff, this is truly a shame) (edited)
According to this, it seems to be a ubuntu thing : https://launchpad.net/ubuntu/+source/sqlite3