New H.264 Tests In FATE

I have just activated 18 new test specs for FATE. One is a test for one variant of the newly supported DPX format. The other 17 are for various samples in the fidelity range extension suite of test vectors, an extension of H.264 that FFmpeg has supported for some time. It should be noted that more samples from this suite should be forthcoming as soon as I finish downloading the whole thing (something I thought I had done a long time ago).