Release 0.4.0

[claudenirmf]

This release includes:

• New "Update Plugin" functionality
• New stereotypes for classes («abstract» and «situation») and associations («bringsAbout» and «triggers»)
• New values for class restrictions (i.e., restrictedTo): intrinsic-mode and extrinsic-mode
• Revisited defaults and enhanced compatibility with gUFO ontology
• Improved menus
• General improvements and bugfixes