fdkaac 0.6.3

2016-08-26 nu774 <honeycomb77@gmail.com>

* update ChangeLog [HEAD -> master]

* bump [origin/master]

* Ticket #23: quit supporting MPEG-2 AOT

2016-08-25 nu774 <honeycomb77@gmail.com>

* fix libfdkaac encoder version check for SBR_RATIO availability

* Use our SBR signaling implementation on old libfdkaac