Separate semilogx and TPR options in ROC plots

See merge request !98

Add Area Under ROC Curve (AUC)

Closes #2

See merge request !97

Add the function called bob.measure.roc_auc_score.
Add the AUC computation to ``bob measure metrics`` command.

Add an alpha option to ROC,DET,EPC figures

See merge request !96

Improve threshold calculation in ROC, DET, and Precision and Recall plots

Closes #58 and #60

See merge request !95

PR - > precision_recall
Internally computes thresholds using both far and frr values for more
accurate plots.
Fixes #60

Fix --figsize help message

See merge request !94

Click scripts fixes

See merge request !93

Fix minimizing threshold

Closes #59

See merge request !92

Fix decimal option in metrics command

Closes #52

See merge request !91

Fixing histogram test

Closes #57

See merge request !90

Add a base class for subplot-based plots

Closes #56

See merge request !89

Update documentation and commands: FAR->FPR, FRR->FNR

Closes #54

See merge request !87

Fix broken commands cref bob.extension!86

See merge request !85