Remove legacy x264 presets

Since we now have the official x264 presets in ffmpeg, there's no reason to
keep around the old ones.

Patch by Lou Logan <lou AT fakeoutdoorsman DOT com>.

Originally committed as revision 25142 to svn://svn.ffmpeg.org/ffmpeg/trunk

ffpresets/libx264-default.ffpreset

-coder=1
-flags=+loop
-cmp=+chroma
-partitions=+parti8x8+parti4x4+partp8x8+partb8x8
-me_method=hex
-subq=7
-me_range=16
-g=250
-keyint_min=25
-sc_threshold=40
-i_qfactor=0.71
-b_strategy=1
-qcomp=0.6
-qmin=10
-qmax=51
-qdiff=4
-bf=3
-refs=3
-directpred=1
-trellis=1
-flags2=+mixed_refs+wpred+dct8x8+fastpskip
-wpredp=2

ffpresets/libx264-fastfirstpass.ffpreset

-coder=1
-flags=+loop
-cmp=+chroma
-partitions=-parti8x8-parti4x4-partp8x8-partp4x4-partb8x8
-me_method=dia
-subq=2
-me_range=16
-g=250
-keyint_min=25
-sc_threshold=40
-i_qfactor=0.71
-b_strategy=1
-qcomp=0.6
-qmin=10
-qmax=51
-qdiff=4
-bf=3
-refs=1
-directpred=3
-trellis=0
-flags2=-bpyramid-wpred-mixed_refs-dct8x8+fastpskip
-wpredp=2

ffpresets/libx264-hq.ffpreset

-coder=1
-flags=+loop
-cmp=+chroma
-partitions=+parti8x8+parti4x4+partp8x8+partb8x8
-me_method=umh
-subq=8
-me_range=16
-g=250
-keyint_min=25
-sc_threshold=40
-i_qfactor=0.71
-b_strategy=2
-qcomp=0.6
-qmin=10
-qmax=51
-qdiff=4
-bf=3
-refs=4
-directpred=3
-trellis=1
-flags2=+wpred+mixed_refs+dct8x8+fastpskip
-wpredp=2

ffpresets/libx264-max.ffpreset

-coder=1
-flags=+loop
-cmp=+chroma
-partitions=+parti8x8+parti4x4+partp8x8+partp4x4+partb8x8
-me_method=tesa
-subq=10
-me_range=24
-g=250
-keyint_min=25
-sc_threshold=40
-i_qfactor=0.71
-b_strategy=2
-qcomp=0.6
-qmin=10
-qmax=51
-qdiff=4
-bf=3
-refs=16
-directpred=3
-trellis=2
-flags2=+wpred+mixed_refs+dct8x8-fastpskip
-wpredp=2

ffpresets/libx264-normal.ffpreset

-coder=1
-flags=+loop
-cmp=+chroma
-partitions=+parti8x8+parti4x4+partp8x8+partb8x8
-me_method=hex
-subq=6
-me_range=16
-g=250
-keyint_min=25
-sc_threshold=40
-i_qfactor=0.71
-b_strategy=1
-qcomp=0.6
-qmin=10
-qmax=51
-qdiff=4
-bf=3
-refs=2
-directpred=3
-trellis=0
-flags2=+wpred+dct8x8+fastpskip
-wpredp=2

ffpresets/libx264-slowfirstpass.ffpreset

-coder=1
-flags=+loop
-cmp=+chroma
-partitions=+parti8x8+parti4x4+partp8x8+partb8x8
-me_method=hex
-subq=6
-me_range=16
-g=250
-keyint_min=25
-sc_threshold=40
-i_qfactor=0.71
-b_strategy=2
-qcomp=0.6
-qmin=10
-qmax=51
-qdiff=4
-bf=3
-refs=1
-directpred=3
-trellis=0
-flags2=+wpred+dct8x8+fastpskip
-wpredp=2