Implement differential (w.r.t. reservoir) linear-mixed analysis with bootstrapping

[paulmueller]

The linear mixed effects analysis need some reshaping:

Changes in user interface:

• Rename the "Treatment" column to "Interpretation"
• Only allow one treatment, i.e. remove the "Treatment i" options from the "Interpretation" column
• Add "Reservoir Control" and "Reservoir Treatment" to the "Interpretation" column
• Help the user to select the right data:
  • if user selects reservoir for treatment/control, tell him to also select reservoir for control/treatment
  • tell the user what will happen to the data (bootstrapping, number of bootstrapping iterations, output is differential deformation or not)

Changes internally:

• Use python scripts from @maikh88 to perform bootstrapping
• Bootstrapping should be performed with seeded random data for reproducibility
• Number of bootstrapping iterations for differential analysis is 5000 1000 (shown, not editable)

[paulmueller]

@maikh88 could you please check out and test the latest development build? I have adapted the user interface to pass the reservoir keywords to lin_mix_mod.py (8977d63).

[paulmueller]

implemented in 0.6.3