Adding most DdMd save/load methods.

Still left: integrators and diagnostics, and configuration.
Fixing small new bug in DdMd::Domain.
Merge branch 'devel' into serialize
Added load/save to DdMd integrators
Added restart code to Simulation, Integrator, TwoStepIntegrator.
Modifying save/load interface for DdMd::Simulation.
Changed writeRestart -> save in DdMd and McMd.
Fixed bug in echo of ParamComposite::load() method.
Add DdMd::SerializeConfigIo class (not yet tested).
Added serialize to DdMd::Group.
Merge branch 'devel' into serialize
Adding read/write to SerializeConfigIo
Merge remote branch 'origin/devel' into devel
Merge branch 'devel' into serialize
Finished and tested DdMd::SerializeConfigIo.

Changed ostream to ofstream in interface of DdMd::ConfigIo.
Attempt to save/load configuration for DdMd restart.

Doesn't work yet.
Small fixes to DdMd ConfigIos and related classes.