Merge pull request #26 from ulvmoen/master

Fixed bug in multizone background model
Merge pull request #27 from ulvmoen/master

Changed eroded_grids from StormContGrid to Volume in multizone background model
CRA-556: Fixed bug with wrongly defined eroded surfaces. Also introduced resampling of all surfaces in multizone model to ensure that truncations work as they should (no surface goes outside its truncation surface).
Merge pull request #31 from RagnarHauge/master

Fix of multizone-bug
CRA-543 Estimate variables in the bounding model

Has not been tested, as well->getPorosity(dymmy) not can be implemented before multizone inversion is ready.
Merge branch 'CRA-543'