Add support for ID3v2 SYLT frames (synchronized lyrics).
Add support for ID3v2 ETCO frames (event timing codes).
Changed cmake_minimum_required from 2.6.0 to 2.8.0.
Add ALBUMARTIST property mapping for MP4

https://code.google.com/p/mp4v2/wiki/iTunesMetadata

Conflicts:
	taglib/mp4/mp4tag.cpp
Suppressed the warning "Policy CMP0022 is not set" on CMake 2.8.12.
Add ALBUMARTIST property mapping for WMA

Conflicts:
	taglib/asf/asftag.cpp
Added some comment about UTF-16 encoding to String::data().
Small fix of a comment

Conflicts:
	taglib/toolkit/tstring.h
Removed a wrong note from a comment in tstring.h.

Conflicts:
	taglib/toolkit/tstring.h
Merge branch 'master' into merge-master-to-taglib2

Conflicts:
	taglib/asf/asftag.cpp
	taglib/mp4/mp4tag.cpp
	taglib/toolkit/tstring.h