Description of problem:

Currently, an entity in Entities.ent takes precedence over a duplicate entity in
a local .ent file. We need the ability to override global entities.

How reproducible:
Always

Steps to Reproduce:
1.Add an entity to a local .ent file with the same name as an entity in one of
the global entity files.
2.Change the value of the local entity
3.Rebuild the book
  
Actual results:
book still displays value of global entity

Expected results:
Book should display value of local entity

Additional info:
I don't know which takes precedence over Entities.ent and
Translateable-entities.ent and nor do I know which should. *Probably*
Translateable but I'm open to suggestions