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
BF: Fix AttributeError in port deduction

A typo in attribute name raised an AttributeError on some platforms.

Found by pylint.
DOC: Fix typo is source comment
Merge pull request #628 from philippwiesemann/fix-colorcal-attributeerror

BF: Fix AttributeError in port deduction
FF: Fix NameError if using TrialHandler with file

A NameError was raised because local function was called with module.

Found by pylint.
DOC: Fix typos in docstrings and source comments
DOC: Add an XSD for PSYEXP XML format

The XSD is only basic and does not care about most of the special cases.
For example there is no check for LoopInitiator and LoopTerminator pairs
and if Routines referenced in Flow are actually definied. But structures
and most of the other restrictions (unique names, enumerated valType and
updates, available Components) should be checked.
TEST: Add a test to check demo PSYEXP XML files