Add support for deleting child objects

package org.jboss.qe.jdg.remote.protobuf.complex;
/* @Indexed */
message Person {
    
    /* @IndexedField(index=true, store=false) */
    required int32 id = 1;
 
    /* @IndexedField */
    required string name = 2;
    
    /* @IndexedField */
    optional string email = 3;
    
    /* @IndexedField(index=true, store=false) */
    repeated PhoneNumber phones = 4;
    /* @Indexed */
    message Address {
 
        /* @IndexedField */
        required string Address = 1;
        
        /* @IndexedField(index=true, store=false) */
        required string City = 2;
        
        /* @IndexedField(index=true, store=false) */
        required string State = 3;
    }
    /* @IndexedField(index=true, store=false) */
    optional Address address = 5;
}
 
/* @Indexed */
message PhoneNumber {
 
    /* @IndexedField */
    required string number = 1;
}

CREATE FOREIGN TABLE Address (
    Address string NOT NULL PRIMARY KEY OPTIONS (NAMEINSOURCE 'address.Address', SEARCHABLE 'Searchable', NATIVE_TYPE 'java.lang.String'),
    City string NOT NULL OPTIONS (NAMEINSOURCE 'address.City', SEARCHABLE 'Searchable', NATIVE_TYPE 'java.lang.String'),
    State string NOT NULL OPTIONS (NAMEINSOURCE 'address.State', SEARCHABLE 'Searchable', NATIVE_TYPE 'java.lang.String'),
    id integer NOT NULL OPTIONS (NAMEINSOURCE 'id', SELECTABLE FALSE, SEARCHABLE 'Searchable', NATIVE_TYPE 'int'),
    CONSTRAINT FK_PERSON FOREIGN KEY(id) REFERENCES Person (id) OPTIONS (NAMEINSOURCE 'address')
) OPTIONS (UPDATABLE TRUE);
 
CREATE FOREIGN TABLE Person (
    id integer NOT NULL OPTIONS (NAMEINSOURCE 'id', SEARCHABLE 'Searchable', NATIVE_TYPE 'int'),
    name string NOT NULL OPTIONS (NAMEINSOURCE 'name', SEARCHABLE 'Searchable', NATIVE_TYPE 'java.lang.String'),
    email string OPTIONS (NAMEINSOURCE 'email', SEARCHABLE 'Searchable', NATIVE_TYPE 'java.lang.String'),
    CONSTRAINT PK_ID PRIMARY KEY(id)
) OPTIONS (UPDATABLE TRUE);
 
CREATE FOREIGN TABLE PhoneNumber (
    number string NOT NULL PRIMARY KEY OPTIONS (NAMEINSOURCE 'phones.number', SEARCHABLE 'Searchable', NATIVE_TYPE 'java.lang.String'),
    id integer NOT NULL OPTIONS (NAMEINSOURCE 'id', SELECTABLE FALSE, SEARCHABLE 'Searchable', NATIVE_TYPE 'int'),
    CONSTRAINT FK_PERSON FOREIGN KEY(id) REFERENCES Person (id) OPTIONS (NAMEINSOURCE 'phones')
) OPTIONS (UPDATABLE TRUE);

DELETE FROM PhoneNumber WHERE id=3