3.0 - Convert configuration into a 'static' file

This is a prototype/working demonstration of converting the various configuration files in CakePHP into a single 'static' file. I use quotes around static as the file is actually PHP. I originally tried to use ini files, but it negatively affected performance in a fairly significant way. An ini file was ~8% slower on my laptop, which didn't seem worth i. Additionally, ini files have more risk in lazy deployment scenarios as there is a risk of the app.ini being exposed accidentally. Interestingly, switching to the single config file boosted performance ~1%, which I assume came from the reduced number of calls to Configure.

I wanted to get a discussion started around this before doing much more work on it.

* Is a single static config file a reasonable thing?
* Do the new methods make sense and seem useful?

Once this issue is settled my plan is to finalize the work around composer and get the code to a point where the cakephp-app repo could be split off and be used for further development. See [this wiki page](https://github.com/markstory/cakephp/wiki/Require-composer) for more details on those plans.