xChrono/xDeltatime migration
xDeltaTime (in xChrono) is use here and there to obtain somme monitoring assesment on code performance. Thus it should not be anylonger in Xfem. It's natural place is in eXlibriss_tools. For example in solverinterface test some test do not need any xfem suff but are linking to this library just because xDeltaTime is locate there.
xChrono.h/cc to migrate in eXlibriss_tools with namespace change.