Pre-release V4.0.b, added Metamodeling profile support

First release where I merged in my work on a metamodeling profile to enable quicker domain-specific profile creation and maintenance for the SysMLHelper collection of profiles:

Change log is:
#267 29-APR-2021: Initial incorporation of Metamodeling Profile developed by MBSE Training for MBSEProfiles work (F.J.Chadburn)
#268 29-APR-2021: Adaptation of Metamodeling Profile to allow for extension of SysML Profile (F.J.Chadburn)

#269 29-APR-2021: Initial work on a system context diagram and association DSL package structure (F.J.Chadburn)

#270 29-APR-2021: Adaptation of Actor Packages to accept rendering of properties using the Metamodeling Profile (F.J.Chadburn)

#271 30-APR-2021: Refinement of context diagram with some automation to enable actor and event selection (F.J.Chadburn)

#272 02-MAY-2021: Adaptation of Requirement and Use Case Packages to render properties using Metamodeling Profile (F.J.Chadburn)

#273 03-MAY-2021: Fix listeners for both SysMLHelper and ExecutableMBSEProfile to stop duplicate double-click handling (F.J.Chadburn)

#274 03-MAY-2021: Fix AddNewMenuStructureContent in the ExecutableMBSE.properties to apply latest menu structure (F.J.Chadburn)

#275 03-MAY-2021: Add a TableL - Context Diagram Flows new term layout to enable tabular view of flows (F.J.Chadburn)

#276 03-MAY-2021: Ensure NamesRegEx for the model allows spaces so that events can be created with spaces (F.J.Chadburn)

#277 04-MAY-2021: Refined icons related to context diagrams (F.J.Chadburn)

#278 04-MAY-2021: Added actor selection dialog to context diagrams if there's a dependency to an actor package (F.J.Chadburn)

#279 10-MAY-2021: Make plugin version more visible in output window when plugin loads (F.J.Chadburn)

#280 10-MAY-2021: Update Add New menus to make profile added diagrams clearer, including allowing Textual Activity (F.J.Chadburn)

#281 11-MAY-2021: Added improved support for detecting and advising wrt ExecutableMBSE profile version (F.J.Chadburn) 

I chose not push this release to Github though, rather keep it for select customers I'm working with while it gets developed.