Small modification to the test cases, now we remove the previous vtu files before running them. Added a subrotuine to limit the saturation. Small improvements in get_int_vel_porous. Test cases passed.
Merge branch 'fluidity-core/MultiFluids_Dev' of github.com:jrper/MultiFluidFluidity into fluidity-core/MultiFluids_Dev
Merge branch 'fluidity-core/MultiFluids_Dev' of github.com:jrper/MultiFluidFluidity into fluidity-core/MultiFluids_Dev