doc/ffserver: mention how to access streams through RTSP
doc/faq: remove "-profile option fails when encoding H.264 video with AAC audio" entry

The error was fixed in commit ce9bd303794fcc94aa232c116bece13c5994b55b
more than one year ago, and does not affect all the currently supported
versions.

In particular, fix trac issue #1535.
avutil/mathematics: fix 2 typos in the doxy

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