NonStorableType Attribute

[mkommend]

Every type that Attic should be able to handle must have the StorableType attribute. However, there is no opposing attribute, for example NonStorableType that explicitly states that this type should not be stored. The use of this attribute would also indicate that the StorableType attribute has not be forgotten, but has been deliberately omitted.

An additional benefit of such an attribute would be that the code analyzer would not issue messages / warnings about missing StorableType attributes on type that are explicitly marked with NonStorableType.