Otherwise TYPE is the name of the atom that denotes the type expected.
If SOURCE is non-nil, get the property on that window instead of from
FRAME. The number 0 denotes the root window.
-If DELETE_P is non-nil, delete the property after retreiving it.
+If DELETE_P is non-nil, delete the property after retrieving it.
If VECTOR_RET_P is non-nil, don't return a string but a vector of values.
Value is nil if FRAME hasn't a property with name PROP or if PROP has