10.2.2: Clarify whether enum types allow multiple members with the same value

CSDL section 10.2.2 only states that the value of the Value attribute is used for sorting.

It does not state whether values of the Value attribute have to be unique within an enum type, and it also does not state whether equality comparison of members of non-flag enum types is done by name or by value.

For flag enum types it states that member combination with the same value are equivalent.