update remaining linear solvers for SolverMeta, new ._parameters class attribute
update remaining linear solvers for SolverMeta, new ._parameters class attribute

- update SchurGeneralized, SchurComplement, MultiProblem - remove
  .process_conf()

rc/sfepy,lokik/sfepy,RexFuzzle/sfepy,BubuLK/sfepy,rc/sfepy,sfepy/sfepy,lokik/sfepy,RexFuzzle/sfepy,BubuLK/sfepy,RexFuzzle/sfepy,lokik/sfepy,vlukes/sfepy,vlukes/sfepy,rc/sfepy,sfepy/sfepy,BubuLK/sfepy,sfepy/sfepy,vlukes/sfepy,lokik/sfepy,RexFuzzle/sfepy