fix depreciation message for rails 3.2 + eval anti-pattern __FILE, __LIN...

fixes these depreciation messages:

DEPRECATION WARNING: Calling set_table_name is deprecated. Please use `self.table_name = 'the_name'` instead. (called from <class:PgConstraint> at (eval):13)
DEPRECATION WARNING: Calling set_primary_key is deprecated. Please use `self.primary_key = 'the_name'` instead. (called from <class:PgConstraint> at (eval):14)
DEPRECATION WARNING: Calling set_table_name is deprecated. Please use `self.table_name = 'the_name'` instead. (called from <class:PgClass> at (eval):2)
DEPRECATION WARNING: Calling set_primary_key is deprecated. Please use `self.primary_key = 'the_name'` instead. (called from <class:PgClass> at (eval):3)
DEPRECATION WARNING: Calling set_table_name is deprecated. Please use `self.table_name = 'the_name'` instead. (called from <class:PgAttribute> at (eval):7)
DEPRECATION WARNING: Calling set_primary_key is deprecated. Please use `self.primary_key = 'the_name'` instead. (called from <class:PgAttribute> at (eval):8)
DEPRECATION WARNING: Calling set_table_name is deprecated. Please use `self.table_name = 'the_name'` instead. (called from <class:PgConstraint> at (eval):13)
DEPRECATION WARNING: Calling set_primary_key is deprecated. Please use `self.primary_key = 'the_name'` instead. (called from <class:PgConstraint> at (eval):14)