Feature/cleanup newton
This MR fixes a couple of issues in the new Newton implementation:
- we add backwards compatible parameter names when working with a ParameterTree
- we fix a violation of the one-definition-rule in
lineSearchStrategyFromString
- we add a backwards compatible handling of
hackbuschReuskenAcceptBest
This MR fixes #165 (closed), #164 (closed), #163 (closed)
These changes should make the transition for users significantly simpler.