StatusReports: Add differentiation of x-axis labels between algorithms: iteration, generation, evaluation

[e-dub]

The following will be used in next version for the graphs produced in ResultsReports:

if Alg in ["MMA", "FFSQP", "FSQP", "GCMMA", "CONMIN", "SLSQP", "PSQP", "KSOPT", "ALGENCAN", "NLPQLP", "IPOPT"]:
    LabelItEval = "Iteration"
elif Alg == "NSGA2":
    LabelItEval = "Generation"
elif Alg[:5] == "PyGMO":
    LabelItEval = "Evaluation"
else:
    LabelItEval = "Evaluation"

Something of this nature shall be done for StatusReports.