Use `_console` instead of `console`

So that we don’t have to rely on external `console.log` presence.
Merge pull request #1 from yuchi/patch-1

Use `_console` instead of `console`
don't use ios 7.1 in tests
0.1.3
Require `assert` only when necessary

This solves some funny cyclic issues because `util` and `assert` use `ti-console` in titaniumifier.