StatSyncing: ChangeLog and BUG: tags for the final merge

This is a cummulative ChangeLog for my GSoC 2012 project, statistics
synchronization.

Individual commits responsible for the changes are earlier, but under
the same git merge.

FEATURES:
* Track dragging support in Unique Tracks tab of the Synchronize Statistics action;
allows you to do a "diff" between collections and transfer missing tracks.
* Amarok now scrobbles tracks in streams if the stream correctly updates
meta-data.
* When scrobbling to Last.fm, Amarok announces suggested tag corrections.
* Ability to scrobble recently played tracks from iPod (and the like) to Last.fm.
* Synchronization of labels and rating between Last.fm and Amarok collections;
play count can be synchronized one-way from Last.fm to Amarok.
* Statistics synchronization between collections, supports rating, first / last
played time, play count and labels.

CHANGES:
* Configure Amarok dialog gets new Metadata tab to grab some weight from the
Collection tab and to configure statistics synchronization.

BUGFIXES:
* Better Last.fm scrobbling behaviour and error reporting due to rewrite,
should fix long-standing problems.
* Update stream meta-data correctly even with phonon-gstreamer back-end.






FIXED-IN: 2.7
DIGEST: Amarok statistics synchronization GSoC project merged with many features
and improvements, please see http://strohel.blogspot.com/search/label/gsoc
for more info and a bunch of screen shots.
GUI: Added statistics synchronization dialogs, split and one more config dialog tab