Changelog: add 2.1

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
MAINTAINERS: update which releases i maintain

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
doc/APIchanges: add 2 missing hashes & versions

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avdevice/pulse_audio_enc: remove double ;

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>