Auto-completion generates brackets inappropriately

[Phil W]

When I have overloaded methods, where one takes a DescribeFieldResult and another that takes an array of DescribeFieldResults, for example, when I type "new D" and use auto-complete, IC should see there is ambiguity and should leave the completion as "new DescribeFieldResult", i.e. without any brackets (it should probably also know that I cannot create a new DescribeFieldResult object directly anyway using "()" so shouldn't ever suggest that).

[Scott Wells]

Should likely be worked in conjunction with #811.