qdoc has no way to independently document QML enumerations

Since QML types can have enumerations there should be a \qmlenum directive to document them, like there is a \qmlproperty directive for properties. Various hacks have been established around this problem. For example:

1. The "enumeration" pseudo type for \qmlproperty - this thing does not exist in actual QML.
2. Listing the enumeration values as part of the documentation of each property that can hold the enumeration - this leads to duplication.
3. Documenting the enumeration as a property. This is wrong because an enumeration is not a property.