Make number of smoothing steps and scaling factor for prolongation of AMG adjustable
Merge remote-tracking branch 'upstream/master'
Merge remote-tracking branch 'upstream/master'
Merge remote-tracking branch 'upstream/master'
Merge branch 'master' of https://github.com/OPM/opm-core
Merge remote-tracking branch 'upstream/master'
Merge remote-tracking branch 'upstream/master'
Merge remote-tracking branches 'origin/master' and 'upstream/master'
Finished customizability in terms of steps and prolongateFactor
Merge remote-tracking branch 'upstream/master'
Merge remote-tracking branch 'upstream/master'

Conflicts:
	opm/core/linalg/LinearSolverIstl.cpp
Merge remote-tracking branch 'origin/master'
Merge remote-tracking branch 'upstream/master'
Unifies the way how AMG is called.

After this patch one can set the prolongation factor for all
AMG calls and the number of smoothing steps for all except
of FastAMG that currently only supports on step.
Fixed spelling
Fixed unused parameters and whitespace issues.
Merge pull request #262 from blattms/unify-amg-calls

Unify amg calls