Changed grammar to generate an AstAbstractActor class as a superclass of
AstActor, AstNetwork and AstExternalActor. AstEntity has a single
feature referring to this class, instead of mutually exclusive features
for each actor kind. This simplifies as lot of logic, since common
features are pushed into the superclass. The main complicating issue is
that AstEntity no longer has a name, it must instead be fetched from the
actor.
Besides FindTopNetworks, these are the regenerated, but otherwise
untouched files.
Merge pull request #2 from hallvard/abstractactor

Abstractactor