Solidifying facility translation

Couple of things:
1. Since I didn't actually have a method in FacilityDec to return whether or not the facility is externally realized, I added that. While I was at it, I wrote javadoc documentation for it, its superclass (Dec) and its superclass ResolveConceptualElement.
2. Revised and changed some documentation in the translation package.
3. Renamed some variables in the translation package for consistency.
4. Removed two constructors from FacilityDec. The first lacked the externally keyword. And the second was a constructor with nothing being passed in.
5. In postArrayTy in the preprocessor, when we create the desugared facility representing a local array type, I simply changed it to call FacilityDecs constructor directly, passing in true for the externally realized flag. ( Since std_array_Realiz doesn't actually exist.)

Thats about it. Let me know if there are any big questions or if you have a huge problem with what I'm trying to do with documentation. (I personally think converting the absyn package to use JavaDocs is something worth doing.)