ASDocs should support amending @inherit and @copy more flexibly

Sometimes, you want to have the standard ASDocs for some inherited property/function, but you want to amend those docs for this particular class. For example, the "left" property on UIComponent behaves slightly different from the way it does elsewhere, since it is a facade over the "left" style.

@inheritDoc can be used to copy the docs from the superclass, and it can be added to ... but only before the @inheritDoc tag. This seems backwards from what you would normally want - any specialized information for a property I would normally put after the standard docs about the property.

@copy can be used to copy the docs from anywhere else, but again you are restricted to putting any additional comments before the @copy tag, where it seems more useful to be able to put more text after the @copy.

I don't understand the current constraints, but it seems useful to be able to add additional text either before or after these tags.