Update for clang compiler.

Corrections based on clang warnings

Extend MathLib linear algebra objects.

This a lightweight pack-unpack class holding two vectors.

This helps with generalization when using essentially same concept of addition.

This simplifies matrix construction in many places because in many cases we need just a bilinear form.

Remove empty base TimeMeasurementBase. Remove virtual qualifiers.

fix getMaxDiagCoeff() in LisMatrix. prepare a diagonal vector by ourself...

Fix lis matrix get max diag coeff