Code / performance improvements

The first commit replaces tabs with spaces. http://www.coffeelint.org/ recommends against using tabs in CoffeeScript.

The second commit is a code improvement and performance. It's not a good idea to allocate a 1,000 item array for every promise. Each of these items is a reference, and references consume memory too. Additionally, if you rely on the length of the array, it's not necessary to keep track with a separate variable.