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.

FEATURE: 240732
FEATURE: 309697
FEATURE: 206249
BUG: 293320
BUG: 285820
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