Merge remote-tracking branch 'qatar/master'

* qatar/master:
  swscale: Provide the right alignment for external mmx asm
  x86: Replace checks for CPU extensions and flags by convenience macros
  configure: msvc: fix/simplify setting of flags for hostcc
  x86: mlpdsp: mlp_filter_channel_x86 requires inline asm

Conflicts:
	libavcodec/x86/fft_init.c
	libavcodec/x86/h264_intrapred_init.c
	libavcodec/x86/h264dsp_init.c
	libavcodec/x86/mpegaudiodec.c
	libavcodec/x86/proresdsp_init.c
	libavutil/x86/float_dsp_init.c
	libswscale/utils.c
	libswscale/x86/swscale.c

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