Load the bake plugin in development

Use the master branch until a stable release (which will coincide with
cakephp 3 stable)
Merge pull request #190 from cakephp/include-bake-plugin

Load the bake plugin in development
Add migrations as require-dev
Better use require here.
Merge pull request #192 from cakephp/master-migrations

Add migrations as "require" composer dependency
Catch missing bake and debug kit plugins

Otherwise the app won't actually work in production, without either the
development-plugins being added or user modifying their bootstrap files.
(users _should_ modify their bootstrap files - but it's likely a
significant number won't and be confused by the missing plugin errors if
they remove the development-only plugins).
Change to debug-mode swith for DebugKit
Remove unused exception
Move debug kit from require to require-dev
Merge pull request #191 from cakephp/catch-missing-plugins

Catch missing bake and debug kit plugins
Update css file
Merge pull request #193 from makamo/patch-1

Update css file
Explicitly specify paths for FileEngine and FileLog.

Use of constants CACHE and LOGS is removed from cache and log packages.
Refs cakephp/cakephp#5458
Merge pull request #194 from cakephp/constants

Explicitly specify paths for FileEngine and FileLog.
Merge branch 'master' of https://github.com/cakephp/app

Conflicts:
	composer.json
	config/bootstrap.php