Start moving app config into an ini file.

This is a proof of concept that application configuration can be put
into static files quite easily.
Add sample email and email transport config.
Remove now unused config files.
Move app.ini to app.ini.php

Using a .php extension prevents webservers from accidentally serving the
configuration file as plain text. This is important for people who do
sloppy deployments where the contents of App/ are accessible from the
webserver.
Remove now useless configuration data.

Once configuration data has been injected into the various classes it is
no longer necessary in Configure. Keeping it in configure only consumes
more memory and give the impression that changing data in configure will
update the other classes.
Add Configure::consume()

This is a simpler/more efficient method for bootstrapping configuration.
Use more efficient methods during bootstrapping.

- Use consume() it is faster than read() + delete().
- Do not merge config as Configure should be empty and merging is
  a waste of time.
Add missing use statement.
Switch to PHP based config files.

There is a significant performance drawback (approx. -8%) to using ini files. Using
PHP based files actually increases performance (approx. 1.1%) as there are fewer calls
to Configure overall.

Using PHP files has the advantage of being harder to screw up in
various deployment scenarios.
Move app.php to app.php.default

Including a half working config file is probably not a good idea. Move
the config file out of the way and force developers to create one.
Update bootstrapping in the case where Config/app.php does not exist.
Update README with setup instructions.
Update to latest 3.0 changes.
Use inline constructors.

Save on a few lines of code with inline constructors.
Change comment style on default config file.
Merge pull request #1575 from markstory/3.0-config

3.0 - Convert configuration into a 'static' file