Doctrine::generateModelsFromDb fails on foreign key relationships with certain table names on Postgresql

Create the following tables:

CREATE TABLE "user" (
id serial PRIMARY KEY,
name varchar(30) NOT NULL
);

CREATE TABLE "group" (
id serial PRIMARY KEY,
name varchar(30) NOT NULL
);

CREATE TABLE "user_x_group" (
id serial PRIMARY KEY,
user_id int NOT NULL REFERENCES "user" ( id ),
group_id int NOT NULL REFERENCES "group" ( id ),
UNIQUE ( user_id, group_id )
);

If you try to run Doctrine::generateModelsFromDb() it will crash with
Uncaught exception 'Doctrine_Import_Builder_Exception' with message 'Missing class name.'

This is caused by the fact that the table 'user' (and 'group' also, for that matter) is escaped with quotes when
passed through pg_get_constraintdef, because 'user' (and 'group') is a reserved word.

A solution would be to modifiy the regexp in Doctrine_Import_Pgsql::listTableRelations so that it strips the quote characters
from identifiers.