A simple Thunderbird extension to export mails to Tracker.

=== How to build a .xpi file ===
From the src/plugins/thunderbird folder, run
git archive --format zip HEAD > tracker-thunderbird.xpi

=== How to test the extension without installing it ===
This method makes development much easier, since it avoids the hassle of
rebuilding the XPI everytime a change is made in the code:
In your Thunderbird profile directory, locate the extensions folder. In that
folder, create a file named trackerbird@bustany.org. In that file, put the full
path to the thunderbird plugin source folder, for example
/home/foobar/Projects/tracker/src/plugins/thunderbird/
Note the trailing slash, it MUST be included for this method to work.
