Fixed some typings with the chain syntax
Underscore: Used tabs vs spaces for my additions

and added explanation in test
Merge branch 'master' of https://github.com/borisyankov/DefinitelyTyped.git
Merge pull request #1581 from tandyjames/master

Fixed some typings with the chain syntax - includes workaround for bug in TS 0.9.5.  Workaround will be removed when TS bug fix ships.