Merge branch 'HandleOutputIssue' into 'master'

NumLib/TimeStepping/Algorithms/FixedTimeStepping.cpp

NumLib/TimeStepping/Algorithms/FixedTimeStepping.h

NumLib/TimeStepping/TimeStep.h

ProcessLib/Output/OutputDataSpecification.cpp

ProcessLib/SteadyStateDiffusion/Tests.cmake

...imes/square_1e1-fixed_timestepping-fixed_output_times.prj

...SteppingFixedOutputTimes/square_1e1_ts_000_t_0.000000.vtu

...SteppingFixedOutputTimes/square_1e1_ts_010_t_0.100000.vtu

...SteppingFixedOutputTimes/square_1e1_ts_020_t_0.200000.vtu

...SteppingFixedOutputTimes/square_1e1_ts_030_t_0.300000.vtu

...SteppingFixedOutputTimes/square_1e1_ts_040_t_0.400000.vtu

...SteppingFixedOutputTimes/square_1e1_ts_050_t_0.500000.vtu

...SteppingFixedOutputTimes/square_1e1_ts_060_t_0.600000.vtu

...SteppingFixedOutputTimes/square_1e1_ts_070_t_0.700000.vtu

...SteppingFixedOutputTimes/square_1e1_ts_080_t_0.800000.vtu

...SteppingFixedOutputTimes/square_1e1_ts_090_t_0.900000.vtu

...SteppingFixedOutputTimes/square_1e1_ts_100_t_1.000000.vtu