Doxygen for Logger::setLevelString() unclear

[carmichaelong]

From @gattia

1. The spacing for setLevelString() is confusing in Doxygen, making it look like trace is only for MATLAB This is not intended by the spacing in the comments in Logger.h (https://github.com/opensim-org/opensim-core/blob/master/OpenSim/Common/Logger.h#L86)

2. Can setLevel() not be used in MATLAB or in all java wrapped cases? Some examples for each function could be useful (perhaps something like https://simtk.org/api_docs/opensim/api_docs/classOpenSim_1_1PlanarJoint.html#aebd231f18a083296d612564a9c60f462)