Updates libkvazaar to pass the exact frame rate to Kvazaar by setting
the numerator and denominator separately instead of a single floating
point number. The exact frame rate is needed for writing timing info to
the bitstream.

Requires Kvazaar version 0.8.1.
Signed-off-by: Arttu Ylä-Outinen <arttu.yla-outinen@tut.fi>