fix to tests for 4.3.0
Merge pull request #105 from enthought/99ce631537d429e5c59efcfa01c9522e7d3be887

Fix PyQt compatibility of tests (PySide specific code).
BUG: Remove the use of the undocumented @ shortcut in our examples.
Merge pull request #110 from enthought/fix-remove-ats

BUG: Remove the use of the undocumented @ shortcut in our examples.
Check if klass is an Interface using isinterface.
Wrong call of isinterface.
FIX: key_event_name: provides an empty string key if no key is found
in the keymap.

This used to throw an error earlier.
Merge pull request #112 from agrawalprash/fix-shift-plus

FIX: key_event_name: provides an empty string key if no key is found
Merge pull request #113 from enthought/adaptation

Adaptation
Merge branch 'master' into python3