fix pivot table + inheritance bean generation

[nguyenk]

Quite a touchy one !

Lets imagine : you have a table A that extends table B. Table B has en foreign key to table C, and table A has a pivot table relation (many to many) also to table C, then :

class B {
   getC() : C {...}
}

class A extends B {
   getC() : array {}
}

This situation throws the following error :

PHP Fatal error:  Declaration of B::getC(): C must be compatible with A::getC(): array in ...