Add tests

[Tieqiong]

See #187

Files that might need more tests (according to coverage report):

• tui.py
• utils.py

In applications:

• pdfgui.py

In control:

• calculation.py
• fitdataset.py
• fitstructure.py
• fitting.py
• organizer.py
• parameter.py
• pdfguicontrol.py
• pdfguimacros.py
• pdflist.py
• plotter.py

In gui (some of them are generated by wxGlade):

• adddatapanel.py
• addphasepanel.py
• bondangledialog.py
• bondlengthdialog.py
• calculationpanel.py
• datasetconstraintpanel.py
• dopingseriespanel.py
• errorreportdialog.py
• errorwrapper.py
• extendedplotframe.py
• fittree.py
• main.py
• mainframe.py
• paneltest.py
• parameterspanel.py
• phaseconfigurepanel.py
• phaseconstraintspanel.py
• phasepanelutils.py
• plotpanel.py
• preferencespanel.py
• rseriespanel.py
• sgconstraindialog.py
• sgstructuredialog.py
• supercelldialog.py
• temperatureseriespanel.py

wxextensions

• autowidthlabelsgrid.py
• listctrls.py
• paneldialog.py
• textctrlutils.py
• validators.py

Details:

In control:

• constraint.py
• controlerrors.py
• pdfcomponent.py
• structureviewer.py

In gui:

• datasetresultspanel.py
• debug options.py
• fitnotebookpanel.py
• journalpanel.py
• outputpanel.py
• phasenotebookpanel.py
• phaseresultspanel.py
• plotpanel.py
• resultspanel.py
• simplecipher.py

wxextensions

• wx12.py

[sbillinge]

we don't normally test gui components (too much work), but it would be good to have tests for functional code.