merged branch gigablah/property-visibility (PR #665)

This PR was merged into the master branch.

Discussion
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Change visibility of `providers` and `booted` to protected

This changes `$providers` and `$booted` in `Application` to protected, which makes it easier to extend.

Commits
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e6902d10 Change visibility of `providers` and `booted` to protected

src/Silex/Application.php

@@ -48,8 +48,8 @@ class Application extends \Pimple implements HttpKernelInterface, TerminableInte
     const EARLY_EVENT = 512;
     const LATE_EVENT  = -512;
 
-    private $providers = array();
-    private $booted = false;
+    protected $providers = array();
+    protected $booted = false;
 
     /**
      * Instantiate a new Application.