modified f for mean and l1 norms
added method to compute spectral norm
finished get_mse.f90
modified code to include mse
put dump.f90 in a module and renamed analyticalsolver
refactored the matrix module
refactored the lhsu module into the grid module
relocated rescale in matrix.f90
relocated eye.f90 into matrix.f90
moved functions in analyticalfunctions
added normalize to matrix module
linear lhs, senstivity density function
 added get_sampling_radius
added construct_sensitivity to senstivity module, not tested yet
unit tested / debugged sensitivity