Added noise profile for sony a6000

The verification was a bit of a hack, because the create hdr option does not (yet) work for the a6000. I created a reference image using image magick and a median filter (convert *.pfm -evaluate-sequence median reference.pfm) instead.

The numbers look good though:
```
DSC04462_ISO100_denoised.pfm : 44.9721
DSC04462_ISO100_noisy.pfm : 43.8342
DSC04463_ISO100_denoised.pfm : 49.7172
DSC04463_ISO100_noisy.pfm : 47.7311
DSC04464_ISO100_denoised.pfm : 49.2977
DSC04464_ISO100_noisy.pfm : 47.3688
DSC04465_ISO100_denoised.pfm : 49.7174
DSC04465_ISO100_noisy.pfm : 47.7318
DSC04466_ISO100_denoised.pfm : 48.2202
DSC04466_ISO100_noisy.pfm : 45.6855
DSC04467_ISO800_denoised.pfm : 44.3805
DSC04467_ISO800_noisy.pfm : 38.6624
DSC04468_ISO800_denoised.pfm : 44.0596
DSC04468_ISO800_noisy.pfm : 38.6099
DSC04469_ISO1600_denoised.pfm : 40.9141
DSC04469_ISO1600_noisy.pfm : 35.5545
DSC04470_ISO1600_denoised.pfm : 40.3991
DSC04470_ISO1600_noisy.pfm : 35.3867
DSC04471_ISO3200_denoised.pfm : 36.9955
DSC04471_ISO3200_noisy.pfm : 32.1188
DSC04472_ISO3200_denoised.pfm : 38.1443
DSC04472_ISO3200_noisy.pfm : 32.556
DSC04473_ISO6400_denoised.pfm : 34.6521
DSC04473_ISO6400_noisy.pfm : 29.2475
DSC04474_ISO6400_denoised.pfm : 34.1485
DSC04474_ISO6400_noisy.pfm : 29.1619
```