XFEM: Implemented computation of enriched N-matrix and added copy
constructors to some XFEM classes.
Domain: Implemented a function Clone() that copies a domain by using the
dynamic data reader. Implemented giveInputRecord in many classes and
moved numberOfGaussPoints to the Element class.
XFEM: Made domain copying work also with several enrichment items.
Cleaned up XFEM input.
XFEM: Updated test cases with cleaned-up syntax.
Merge branch 'master' of https://github.com/Micket/oofem