Reducing line length to within 80 chars

This is supposedly recommended by the Python coding standards.  In some
cases this made the code a bit easier to read in that some long parts were
turned into variables which could then be given descriptive names.
No selection query when there are no search results.
Correcting spacing issues around operators, commas etc
Adding missing docstrings to modules, classes and methods
Merge remote-tracking branch 'paul/long_line_fix'

Conflicts:
	modules/controller.py
Merge remote-tracking branch 'paul/spacing_fixups'

Conflicts:
	modules/model.py
Merge remote-tracking branch 'paul/add_missing_docstrings'

Conflicts:
	modules/controller.py