Add conversion routines for new audio formats.
Add conversion routines for new audio formats.

These only doing conversion _from_ the new types mlt_audio_s32le and
mlt_audio_f32le. There are no plans at the moment for conversion into
them, but it is certainly not out of the question.

anba8005/mlt,ttill/MLT,j-b-m/mlt,ttill/MLT-roto-tracking,gmarco/mlt-orig,siddharudh/mlt,ttill/MLT,zzhhui/mlt,ttill/MLT,wideioltd/mlt,wideioltd/mlt,mltframework/mlt,mltframework/mlt,gmarco/mlt-orig,ttill/MLT-roto-tracking,siddharudh/mlt,anba8005/mlt,j-b-m/mlt,siddharudh/mlt,zzhhui/mlt,gmarco/mlt-orig,wideioltd/mlt,j-b-m/mlt,j-b-m/mlt,ttill/MLT,zzhhui/mlt,anba8005/mlt,j-b-m/mlt,mltframework/mlt,ttill/MLT-roto-tracking,ttill/MLT,ttill/MLT-roto-tracking,ttill/MLT,wideioltd/mlt,anba8005/mlt,j-b-m/mlt,ttill/MLT-roto-tracking,xzhavilla/mlt,j-b-m/mlt,j-b-m/mlt,zzhhui/mlt,gmarco/mlt-orig,ttill/MLT,xzhavilla/mlt,zzhhui/mlt,zzhhui/mlt,wideioltd/mlt,mltframework/mlt,ttill/MLT-roto-tracking,xzhavilla/mlt,siddharudh/mlt,ttill/MLT-roto-tracking,anba8005/mlt,xzhavilla/mlt,zzhhui/mlt,j-b-m/mlt,anba8005/mlt,mltframework/mlt,siddharudh/mlt,wideioltd/mlt,xzhavilla/mlt,mltframework/mlt,mltframework/mlt,siddharudh/mlt,xzhavilla/mlt,anba8005/mlt,siddharudh/mlt,zzhhui/mlt,ttill/MLT-roto-tracking,wideioltd/mlt,ttill/MLT-roto-tracking,xzhavilla/mlt,siddharudh/mlt,xzhavilla/mlt,anba8005/mlt,ttill/MLT,mltframework/mlt,gmarco/mlt-orig,mltframework/mlt,mltframework/mlt,ttill/MLT,xzhavilla/mlt,gmarco/mlt-orig,wideioltd/mlt,wideioltd/mlt,gmarco/mlt-orig,zzhhui/mlt,anba8005/mlt,j-b-m/mlt,siddharudh/mlt,gmarco/mlt-orig,gmarco/mlt-orig