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/private/support/JobPrivate.h

@@ -0,0 +1,41 @@
+/*
+ * Copyright 2015, Haiku, Inc.
+ * Distributed under the terms of the MIT License.
+ */
+#ifndef _JOB_PRIVATE_H_
+#define _JOB_PRIVATE_H_
+
+
+#include <Job.h>
+
+
+namespace BSupportKit {
+
+
+class BJob::Private {
+public:
+	Private(BJob& job)
+		:
+		fJob(job)
+	{
+	}
+
+	void SetTicketNumber(uint32 ticketNumber)
+	{
+		fJob._SetTicketNumber(ticketNumber);
+	}
+
+	void ClearTicketNumber()
+	{
+		fJob._ClearTicketNumber();
+	}
+
+private:
+			BJob&				fJob;
+};
+
+
+}	// namespace BSupportKit
+
+
+#endif // _JOB_PRIVATE_H_

headers/private/support/JobQueue.h

@@ -0,0 +1,66 @@
+/*
+ * Copyright 2011-2015, Haiku, Inc.
+ * Distributed under the terms of the MIT License.
+ */
+#ifndef _SUPPORT_PRIVATE_JOB_QUEUE_H_
+#define _SUPPORT_PRIVATE_JOB_QUEUE_H_
+
+
+#include <Locker.h>
+#include <SupportDefs.h>
+
+#include <Job.h>
+
+
+namespace BSupportKit {
+
+namespace BPrivate {
+
+
+class JobQueue : private BJobStateListener {
+public:
+								JobQueue();
+	virtual						~JobQueue();
+
+			status_t			InitCheck() const;
+
+			status_t			AddJob(BJob* job);
+									// takes ownership
+			status_t			RemoveJob(BJob* job);
+									// gives up ownership
+
+			BJob*				Pop();
+									// caller owns job
+
+			void				Close();
+
+private:
+								// BJobStateListener
+	virtual	void				JobSucceeded(BJob* job);
+	virtual	void				JobFailed(BJob* job);
+
+private:
+			struct JobPriorityLess;
+			class JobPriorityQueue;
+
+private:
+			status_t			_Init();
+
+			void				_RequeueDependantJobsOf(BJob* job);
+			void				_RemoveDependantJobsOf(BJob* job);
+
+			BLocker				fLock;
+			uint32				fNextTicketNumber;
+			JobPriorityQueue*	fQueuedJobs;
+			sem_id				fHaveRunnableJobSem;
+
+			status_t			fInitStatus;
+};
+
+
+}	// namespace BPrivate
+
+}	// namespace BSupportKit
+
+
+#endif // _SUPPORT_PRIVATE_JOB_QUEUE_H_