Handle `name` and `"char"` column types in the PostgreSQL adapter.

`name` and `"char"` are special character types used internally by
PostgreSQL and are used by internal system catalogs. These field types can sometimes show up in structure-sniffing queries that feature internal system structures or with certain PostgreSQL extensions. I ran across this issue when using PostGIS, as its `geography_columns` view uses the `name` type for some of its fields. It would be nice if this could be merged into the 4-0-stable branch as well if possible. 

More details on the `name` and `"char"` types can be found at the bottom of this page:

http://www.postgresql.org/docs/9.2/static/datatype-character.html