Allow to create temporary references

[Matthias Schoettle]

Right now, in message views, it is only possible to create temporary variables with primitive types. Existing class types can only be chosen based on existing properties (e.g., temporary assignments, association ends etc.).

However, it might be necessary to create a temporary reference to do something/more with it later. For example, initialize it with null.

There could be two solutions to this:

1. In the selector, after tapping on the + button, in addition to the primitive types, show all possible ObjectTypes.
2. In the selector, after tapping on the + button, show one option (e.g., Class or something else), followed by a selector with all possible ObjectTypes.

[Matthias Schoettle]

References #402: Adds utility class to be used for retrieving available choices for an aspect.

Instead of filtering out the choice of values for property descriptors, the interface should be used to have a clear definition of how available choices are determined.

→ <<cset d75dd039981a>>

[Matthias Schoettle]

Resolves #402: Adds support to allow creation of temporary references.

The selector shows all available types and the controller creates the appropriate TemporaryProperty depending on the type of the chosen type. I.e., for primitive types an Attribute is used, for classes a Reference.

→ <<cset 87b47dda6347>>

[Matthias Schoettle]

References #402: Adds additional test case to cover Reference creation.

→ <<cset 1587053afe5d>>

[Matthias Schoettle]

References #269: Moves making name unique to createTemporaryProperty to ensure consistency.

Moves it out of MessageController. Renames public method to createAndAddTemporaryProperty.

refs #407 refs #402

→ <<cset 13d3eb775a19>>

[Matthias Schoettle]

References #402: Adds utility class to be used for retrieving available choices for an aspect.

Instead of filtering out the choice of values for property descriptors, the interface should be used to have a clear definition of how available choices are determined.

→ <<cset d75dd039981a>>

[Matthias Schoettle]

Resolves #402: Adds support to allow creation of temporary references.

The selector shows all available types and the controller creates the appropriate TemporaryProperty depending on the type of the chosen type. I.e., for primitive types an Attribute is used, for classes a Reference.

→ <<cset 87b47dda6347>>

[Matthias Schoettle]

References #402: Adds additional test case to cover Reference creation.

→ <<cset 1587053afe5d>>

[Matthias Schoettle]

References #269: Moves making name unique to createTemporaryProperty to ensure consistency.

Moves it out of MessageController. Renames public method to createAndAddTemporaryProperty.

refs #407 refs #402

→ <<cset 13d3eb775a19>>

[Matthias Schoettle]

Merged in Issues/269-402-Temporary-References (pull request #91)

[Matthias Schoettle]

References #402: Prevents same classifier to show up several times by resolving them if they already exist in the current aspect.

→ <<cset ed6ea3bfd205>>