Don't generate different tags for type declaration and definition

[fakedrake]

Hasktags will produce two separate tags for

f :: Type
f = undefined

I can't think of a case where this is practical excapt maybe in the rare case where we have something like

f :: Type
-- Here 
-- Is
-- A
-- Lot
-- Of
-- Documentation
f = undefined

But even here both tags actually refer to the same definition. Maybe we could have a flag to switch between different ways of handling this? (I can implement this I just want to discuss it before I do)

[jhenahan]

I'm not seeing this behavior in 0.70.1. That may have been a consequence of a regression I introduced in 0.70. Would you be able to try with 0.70.1 and let me know if you're still seeing it?