[Tracker] Switch to LGPL for libtracker-common, libtracker-db, and libtracker-data

[Jürg Billeter <j bitron ch>]

Hi all,

we're considering to allow applications to query the data in Tracker
using a direct access library at some point in the future, i.e., a
public library that directly reads from the SQLite database instead of
using D-Bus.

To prevent possible licensing issues with that library, we'd like to
relicense the code used in the internal libraries libtracker-common,
libtracker-db, and libtracker-data from `GPLv2 or later' to `LGPLv2 or
later'.

We therefore kindly ask everyone who has contributed code used in any of
the aforementioned libraries to reply with a mail to allow us to go
forward with the relicensing. We'll send individual mails to
contributors that we've determined from the change log.

Thanks for your contributions,

JÃrg