* Read, create and update methods of GeneralGrassCoverErosionInwardsInput used for persisting to and from GrassCoverErosionInwardsFailureMechanism. ** Adapted Read method to be consistent to how GrassCoverErosionInwardsFailureMechanism read extension method is used. Related to Issue [WTI-655] git-svn-id: https://repos.deltares.nl/repos/WettelijkToetsInstrumentarium/trunk@4095 5a3db67b-de53-47b5-99c8-a1c30a6650e2