Moved BJob, and JobQueue into the support kit.

* Put it in the BSupportKit namespace, following the style introduced
  with the package kit for now.
* The BSupportKit::BJob class no longer knows about the package kit's
  Context class. However, the BPackageKit::BJob class does.
* Due to the namespace juggling, a lot of files had to be touched.
* The JobQueue class remains private.
* Due to the way Haiku is built on itself, you cannot build this change
  under Haiku with an older release.

headers/os/package/AddRepositoryRequest.h

@@ -1,5 +1,5 @@
 /*
- * Copyright 2011, Haiku, Inc.
+ * Copyright 2011-2015, Haiku, Inc.
  * Distributed under the terms of the MIT License.
  */
 #ifndef _PACKAGE__ADD_REPOSITORY_REQUEST_H_
@@ -36,7 +36,7 @@ public:
 
 protected:
 								// BJobStateListener
-	virtual	void				JobSucceeded(BJob* job);
+	virtual	void				JobSucceeded(BSupportKit::BJob* job);
 
 private:
 			BString				fRepositoryBaseURL;