These were a bit hidden, but found. They add a few more customization
options and kamg as a sequential solver. The latter will be broken if
we use update, though.
Previously, it got passed the weights only needed for CPR.
Additionally those were passed with the parameter tree to the
update method and constructor.
Now the CPR constructor gets a function to use for recalculating
the weights and the property is not changed. Unfortunately this
means that the preconditioner creators of the factory get another
parameter.
This fixes name clashes with DUNE's own factory that is introduced
in DUNE 2.7. Hence it closes issue #2266.
BTW: Dune's factory has more template parameters than ours.
This replaces the makePreconditoner() function. The main advantage
is that it is extensible, making it easy to for example add new
preconditioners to the factory at runtime. It supports both parallel
and serial preconditioners.
