Duck-types KrylovSubspace. (#2)
Provides ModifiedGramSchmidt (= Householder) as the new default orthogonalization method
Complete duck-typing of simple and Lanczos methods
- Removed unnecessary specializations of parametric types.
- Uniformly implemented ConvergenceHistory returns
- Renamed loop iterator to iter instead of k
- General cleanup
- XXX Commented out failing tests!