Move back example interface outside hysop package (environment configuration by the interface without importing hysop)

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

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)

Update of operators (continuous and discrete) : init and setup ok to fit with the new way to handle topology and discrete fields