Add connection for new SQLite based data storage.
Start adding tables for sqlite storage.

We'll only need two tables to start with. A request has many panels.
Add lazy way to get schema made on demand.

Re-use fixtures to build runtime database on demand. This lets me not
have to worry about including a database in the plugin and if there are
'migrations' people can delete their DB and start over :)
Use UUIDs instead of integers.

Using UUID's will allow the request id to be generated before data is
saved into the database, allowing the panel initialization script to
contain the correct id.
Starting to rework the panels and toolbar in general.

* Move toolbar installation into the bootstrap file.
* Make toolbar use event subscribers instead of existing hooks. This
  breaks compatibility and functionality pretty hard. But that's OK for
  now as this is mostly a work in progress.
* Create a PanelRegistry as it is a separate concern.
Add sketch of new debugtoolbar data collector.

This new approach does a few things differently:

* Data is stored in a SQLite database on each request.
* The request id is pre-generated allowing it to be added to the page
  so toolbar state can be easily loaded.
* The main toolbar and all the panels will do their introspection via
  events. I hope to remove the component entirely and have the entire
  functionality of debug kit enabled during app bootstrap.
Merge pull request #192 from cakephp/sqlite-storage

Sqlite storage