Updated StochastSchema.xsd so that mean is optional and either standard deviation or a variation coefficient can be optionally defined. Related to Issue [
WTI-1218]
git-svn-id:
https://repos.deltares.nl/repos/WettelijkToetsInstrumentarium/trunk@8901 5a3db67b-de53-47b5-99c8-a1c30a6650e2
Former-commit-id: 3413e104edd41c143a9486526ea7c57cb7b230b5
Former-commit-id: c8f1ca3376ffdf9cc3c7a692f0f08a701d5f2533