Its not something that appears to be vastly desired or needed in the core since this is the first time its been asked for, so it should be in a plugin, at least to start with.
Okay! What are the general reasons for when it is better to make a plugin instead of a core feature? E.g. there is a plugin which highlights double-click-selected text in the editor, but I always asked why this is not a core feature because I think it is very helpful for many coders.
@kugel- Could you please give me a link to the exact plugin?