#148 Autocomplete class instance members

[Tobias Bexelius]

When writing a class instance like this

instance Monad A where
| <-- The caret

It would be great if the autocomplete could suggest only the members of the class (incl. associated types) at the point of the caret above. I guess it might require some special parsing of an unfinished statement, but I think it would be worth it. (Or point me in the right direction, and I could have a look at it... :) )

[Tobias Bexelius]

I have an alternative idea that probably is easier to implement:

Add an quick fix for the warning issued by GHC that some methods in an instance arent implemented (No explicit method nor default method for `fmap') that just adds stubs for all those methods, using " = undefined " as implementation

Adding = undefined quickfix might be useful for a top level type signature without a defenition as well (The type signature for `f' lacks an accompanying binding).