* refactored cpu_kernel.h multiple times, since I didn't want to have something link this in src/multiviewnative.cpp
if(condition_known_outside_loop_body)
	do_this();
else
	do_else();
  --> turns out that compiler optimisation and branch prediction do this quite well
  --> might be subject to later refactoring

* added benchmark suite for cpu deconvolution (using all cores present)
fixed bug in public API where plain_final_values was used incorrectly instead of regularized counterpart; restructured benchmark a bit so that quality metrics are printed during deconvolution; moved thread relevant fftw calls into static method according to fftw documentation http://www.fftw.org/fftw3_doc/Usage-of-Multi_002dthreaded-FFTW.html#Usage-of-Multi_002dthreaded-FFTW
removed fftw_plan_with_nthreads call from forward/backward methods into static method (so it is called only once); starting to work on the gpu deconvolution
this commit contains a broken library (in the middle of implementing the GPU based convolution), internal structure of the gpu part will change in the following commits
reworked gpu api completely, cpu api still completes all tests, gpu convolve api fails tests
added test_gpu_deconvolve (GPU API not working 'yet')