[jshintrc] Allow functions to be used before being declared

This pull request changes the JSHint config to allow functions to be used before being declared. Unlike a variable, a function has its body hoisted along with its name, so it's safe to call it earlier in your code. I often keep functions near the end of my files to keep them out of the way from the main code.

It seems this should be allowed per the styleguide. I couldn't find anything that says not to do this. From the "Hoisting" section:
> Function declarations hoist their name and the function body.

Thoughts?