BF: Fix TypeError

The ERROR constant was called instead of the error function.

Found by pylint.
ENH: Fix typo in error message
DOC: Fix typo in docstring
DOC: Fix typos in docstrings
DOC: Fix typos in source comments
DOC: Fix typos in source comments
BF: Fix AttributeError in test main

An AttributeError was raised because the test main was not adapted after
a change of ListWidget to be a GlobSizer instead of just containing one.

Found by pylint.
BF: Fix NameError

A NameError was raised because logging was used but not imported.

Found by pylint.
DOC: Fix typos in source comments and log message
BF: proper positioning of popup menu when flow panel is at the top
Merge pull request #627 from jeremygray/bf-topflow-popup-menu-location

BF: proper positioning of popup menu when flow panel is at the top
Merge pull request #626 from philippwiesemann/fix-dialogs-errors

BF: Fix AttributeError and NameError
Merge pull request #624 from philippwiesemann/fix-basevisual-typeerror

BF: Fix TypeError