[PATCH] Local key relations without modifed fields but with modified relations are not saved

Assume the following test setup:

[Email] * — 1 [Author] 1 — * [Book]

Assume further that you have a new Email, Author and Book object. Email and book have modified fields, author does not, except for the foreign key relation.

Now, when you save the Email object, the related Author is not saved because isModified($deep = false) returns false since no local field is modified. The solution is to pass the parameter $deep = true to isModified().

Patch and test case are attached. No existing test is broken by this fix.

PS: This patch fixes the correlated bug that objects with I18N behaviour are not saved if only their Translation objects are modified, but not their own fields.