Spim deconvolution on gpgpu

* Added logic to src-plugins/SPIM_Registration/src/main/java/fiji/plugin/Multi_View_Deconvolution.java how to select GPU on multi-GPU hosts (the Nvidia GPU with the highest ComputeCapability is selected here)
* added log statements to src-plugins/SPIM_Registration/src/main/java/mpicbg/spim/postprocessing/deconvolution2/LRFFT.java and src-plugins/SPIM_Registration/src/main/java/mpicbg/spim/postprocessing/deconvolution2/LRFFTThreads.java to clearify runtime spent on CPU or GPU