Update the python wrappers not try to wrap the old model system.
Fix a warning and a doc link.
Merge topic 'fix-warning'

96b2c17 Fix a warning and a doc link.
Fix the Python environment for the tutorial.

... and tweak the tutorial text.
Merge topic 'fix-test'

80ab4f9 Fix the Python environment for the tutorial.
Remove smtk::attribute knowing about the legacy model system.
Remove old model items mask code from attribute::Defintion
Remove the reference smtk::model::Model from attribute::Manager.

Instead you should associate an attribute::Manager to a smtk::model::Manager.
Switch over to XML V2 readers that don't use old model system.

Keep the old readers around as we need add them in just for
attribute system reading support if no model association exists.
Convert of the model group serialization in the xml reader/writer.
Move view over to the new model and new model mask bits.
Update view tests to use the new model code.
update attribute tests to not refer to old model system.
Port the qt AssoicationWidget over to the new model system.
Update qtAttributePreview do not refer to old model system.
Actually remove the old model files.
Merge topic 'remove_old_model'

6fd8ab1 Actually remove the old model files.
a86fb9b Update qtAttributePreview do not refer to old model system.
76ffaed Port the qt AssoicationWidget over to the new model system.
dd609fd update attribute tests to not refer to old model system.
529555e Update view tests to use the new model code.
0544d82 Move view over to the new model and new model mask bits.
f0c0f15 Convert of the model group serialization in the xml reader/writer.
a97e210 Switch over to XML V2 readers that don't use old model system.
3c819b9 Remove the reference smtk::model::Model from attribute::Manager.
ae3b706 Remove old model items mask code from attribute::Defintion
e515de0 Remove smtk::attribute knowing about the legacy model system.
746d7c7 Update the python wrappers not try to wrap the old model system.
Move pugixml to thirdparty and drop the version number in the directory name.
Update users of pugixml to new folder name.
Move the cgm and remus bridge to smtk/bridge.