fix problem with solver reastart, variable was not reset.
Also, the time step does only grow moderately after a solver restart.
remove unused typedef to avoid compiler warning and keep code clean.
Merge pull request #671 from dr-robertk/PR/timestepcontrol-fixrestart

Fix solver restart counter.
Merge pull request #672 from dr-robertk/PR/remove-unused-typedef-warning

remove unused typedef to avoid compiler warning and keep code clean.