Update winjs.d.ts to include a large number of missing functions from the List class.
Merge pull request #1074 from wiredprairie/patch-3

Update winjs.d.ts to include a large number of missing functions from th...
make signatures --noImplicitAny friendly
add missing methods
define interface for 'this' object when executing a task
Merge pull request #1079 from varju/gruntjs

Gruntjs signature improvements