Support conditional output if BubbleWrap is installed

[markrickert]

This is a backwards compatible and non-breaking change that does the following:

1. Detects if the user is using the BubbleWrap gem.
2. If not, it does the same thing it has always done.
3. If so, it checks to see if BW.debug is set to true.
4. If not, the the ap call will not output anything.
5. If so, it will allow the console output to proceed as normal.

This is based on my blog post: http://blog.markrickert.me/leaving-debug-code-in-production-apps and I figured that making it automatic would be useful.

I hope you merge this and release a new gem version! I know a few people that have been pestering me to implement this functionality in this gem.

cc/ @GantMan

[GantMan]