lavfi/drawtext: do not allocate FT_Glyph, but keep it in the Glyph structure

Slightly simplify.
tools/ffeval: print computed value even in case of error

This is useful for debugging purposes.
doc/protocols: document unit of timeouts for ftp and http

Signed-off-by: Lukasz Marek <lukasz.m.luki2@gmail.com>
Signed-off-by: Stefano Sabatini <stefasab@gmail.com>
Fix standalone compilation of the amv encoder.