removed README_inversion_package_list_of_things_to_do.txt
updates tomography routine and checks material definitions in nummaterial_velocity_file; fixes #302
Merge pull request #304 from komatits/devel

removed README_inversion_package_list_of_things_to_do.txt
fixes CPML when using Deville routine in fluids
uses Deville routines by default, setting USE_DEVILLE_PRODUCTS to .true. in constants.h.in
Merge branch 'devel' of https://github.com/geodynamics/specfem3d into devel