Clean up threading

* Rename everything.
    * Strip J prefix.
    * Change UpperCamelCase functions to lowerCamelCase.
  * Remove global (!) semaphore count mutex on OSX.
  * Remove semaphore count getter (unused, unsafe, depended on internal
    API functions on Windows, and used a hack on OSX).
  * Add `Atomic<type>`.
  * Make `Thread` handle thread names.
  * Add support for C++11 multi-threading.
  * Combine pthread and win32 sources.
  * Remove `ThreadStarted` (unused, unneeded).
  * Move some includes from the headers to the sources.
  * Move all of `Event` into its header (allows inlining with no new includes).
  * Make `Event` use `Semaphore` (except on Windows).
  * Move some porting functions into `Thread`.
  * Integrate logging with `Thread`.
  * Add threading test.

src/threading/semaphore.h

@@ -0,0 +1,52 @@
+/*
+Minetest
+Copyright (C) 2013 sapier <sapier AT gmx DOT net>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#ifndef THREADING_SEMAPHORE_H
+#define THREADING_SEMAPHORE_H
+
+#if defined(_WIN32)
+	#include <windows.h>
+#elif defined(__MACH__) && defined(__APPLE__)
+	#include <mach/semaphore.h>
+#else
+	#include <semaphore.h>
+#endif
+
+
+class Semaphore {
+public:
+	Semaphore(int val=0);
+	~Semaphore();
+
+	void post(unsigned int num=1);
+	void wait();
+	bool wait(unsigned int time_ms);
+
+private:
+#if defined(WIN32)
+	HANDLE semaphore;
+#elif defined(__MACH__) && defined(__APPLE__)
+	semaphore_t semaphore;
+#else
+	sem_t semaphore;
+#endif
+};
+
+#endif
+