ffserver_config: fix line lengths

Signed-off-by: Reynaldo H. Verdejo Pinochet <reynaldo@osg.samsung.com>
ffserver_config: simplify some if true conditions

Signed-off-by: Reynaldo H. Verdejo Pinochet <reynaldo@osg.samsung.com>
ffserver_config: add fixme on buffer_aggressivity/eq deprecation

Signed-off-by: Reynaldo H. Verdejo Pinochet <reynaldo@osg.samsung.com>
README: fix 2 typo in the doc/examples sentence
lavf/flvenc: fail in case the muxed packet is too big

Avoid the creation of files which cannot be successfully decoded by
ffmpeg, for example generated with:
ffmpeg -f lavfi -i sine -af "aselect='not(between(t,100,500))',aresample=min_comp=0.001:min_hard_comp=0.100000" -acodec pcm_s16le -t 1000 -y out_audio.flv