single_project has undefined names

[mdickinson]

The single_project code has several undefined names.

mirzakhani:envisage mdickinson$ flake8 .
./envisage/ui/single_project/project_plugin.py:381:34: F821 undefined name 'ActionSetManager'
./envisage/ui/single_project/project_plugin.py:382:28: F821 undefined name 'DefaultMenuBuilder'
./envisage/ui/single_project/project_plugin.py:384:51: F821 undefined name 'NO_SELECTION_MENU_ID'
./envisage/ui/single_project/project_plugin.py:396:40: F821 undefined name 'SyncProjectSelection'
./envisage/ui/single_project/action/save_as_project_action.py:77:15: F821 undefined name 'SaveAsAction'
./envisage/ui/single_project/action/save_as_project_action.py:104:9: F821 undefined name 'logger'
./envisage/ui/single_project/action/save_project_action.py:74:15: F821 undefined name 'SaveAction'
./envisage/ui/single_project/action/save_project_action.py:99:9: F821 undefined name 'logger'

See also: #124, and various other single_project-related issues. I think we should seriously consider removing single_project for Envisage 5.0.0

[rahulporuri]

closed by #331