9/12 push db validation up to Naming_table
Summary:
This diff stack gets rid of global sharedmem state "NamingTableDatabaseSettings", which stores the path to the naming DB.
The function `Naming_sqlite.set_db_path` is bad because a leaf function like this shouldn't be setting such globally important state as db_path. Therefore my goal is to move "set_db_path" higher up the callstack. To achieve this, I first have to clean up set_db_path, to make it a pure function that only sets the db_path, and move its side effects into its callers. That's what this diff does.
Reviewed By: arxanas
Differential Revision:
D21192324
fbshipit-source-id:
3f4c72a12cef3e52f0ec09bdf6dafab13c6b327a