changed: drop seqlu in favor of new upstream template InverseOperator2Preconditioner
changed: move fastamg setting to linsolver settings where it belongs
added: allow switching AMG smoothers from commandline
modernize pointer handling

use shared_ptr instead of manual delete's
abuse the preprocessor to keep template boilerplating at acceptable levels
changed: make the matrixops helpers a normal c++ class

no templating going on here, no reason to keep it header only