fix install process
review tests process
fix (partial) arnoldi stuff which depends on lapack
...

- fix bug poisson
- comment googletests (temp)
- comment fftw extra libs (fftwq ..., temp)

Fix penalisation/subsets (partially)
Update doc (sphinx)
Almost all tests ok except:
	 22 - mpi_test_advec_scales (Failed)
	 77 - test_advection_nullVelocity (Failed)
	 79 - test_advection_randomVelocity (Failed)