Testing upscale_perm: Change to periodic BCs for test on PeriodicTilted.grdecl
Add grid models to be used for testing upscale_perm
Add new reference solutions for testing upscale_perm
Add more tests for upscale_perm

Also write a macro for testing upscale_perm on different models.
This change makes it easier to add more tests and to keep the code tidy.
Chop test model 'hummockyexample.grdecl'

This reduce the computation time considerably.
Increase tolerance to avoid false negatives
Small changes in documentation
Use absolute tolerance instead of relative tolerance

Using relative tolerance is problematic when comparing small numbers.
Change name of hummocky model
Untabify
Untabify again
Merge pull request #61 from laods/add_tests

Add more regression tests for upscaling applications