Completion in reference comments and imports

[DanielRosenwasser]

/// <reference path="

If requesting completion here, we should get ., .., and any .ts files at the current directory location.

If requesting completion after a \ or / in the path, if the path up until the last / or \ is valid, we should get ., .. and any .ts files in that path.

[danquirk]

Absolutely. I get this today in Sublime via https://github.com/BoundInCode/AutoFileName. It's handy even outside ///.

[NoelAbrahams]

Is this the same as #188?

[DanielRosenwasser]

Thanks for the heads up @NoelAbrahams - looks like @ahmad-farid is already assigned this task.