Remove ki_mutex.h and associated includes

REMOVED: ki_mutex.h since all mutexes now use std::mutex

Documentation/development/technical_todo.md

@@ -23,9 +23,6 @@ Newer C++ versions include features that make some of our current code unnecessa
 This C++ standard version is already used by KiCad, but much code that pre-dates
 the version switch exists and can be tidied.
 
-* `MUTEX` can use [`std::mutex`](https://en.cppreference.com/w/cpp/thread/mutex)
-  and remove the Boost mutex dependency and the whole `ki_mutex.h` header in
-  favour of `<mutex>`.
 * [`std::auto_ptr`](https://en.cppreference.com/w/cpp/memory/auto_ptr)
   should be changed to [`std::unique_ptr`](https://en.cppreference.com/w/cpp/memory/unique_ptr).
   `auto_ptr` is removed entirely in C++17.

include/footprint_info.h

@@ -34,7 +34,6 @@
 
 #include <import_export.h>
 #include <ki_exception.h>
-#include <ki_mutex.h>
 #include <kicad_string.h>
 #include <sync_queue.h>
 #include <lib_tree_item.h>

include/ki_mutex.h

@@ -1,56 +0,0 @@
-/*
- * This program source code file is part of KiCad, a free EDA CAD application.
- *
- * Copyright (C) 2013-2014 SoftPLC Corporation, Dick Hollenbeck <dick@softplc.com>
- * Copyright (C) 1992-2014 KiCad Developers, see CHANGELOG.TXT for contributors.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version 2
- * 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 General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, you may find one here:
- * http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
- * or you may search the http://www.gnu.org website for the version 2 license,
- * or you may write to the Free Software Foundation, Inc.,
- * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
- */
-
-#ifndef KI_MUTEX_H_
-#define KI_MUTEX_H_
-
-
-/// Establish KiCad MUTEX choices here in this file:
-///    typedef MUTEX and typedef MUTLOCK.
-///
-/// Using an unnamed resource is easier, providing a textual name for a
-/// constructor is cumbersome, so we make choice on that criteria mostly:
-
-#if 1
-
-// This is a fine choice between the two, but requires linking to ${Boost_LIBRARIES}
-
-#include <boost/interprocess/sync/interprocess_mutex.hpp>
-#include <boost/interprocess/sync/scoped_lock.hpp>
-
-typedef boost::interprocess::interprocess_mutex     MUTEX;
-typedef boost::interprocess::scoped_lock<MUTEX>     MUTLOCK;
-
-#else
-
-// This choice also works.
-
-#include <wx/thread.h>
-
-typedef wxMutex             MUTEX;
-typedef wxMutexLocker       MUTLOCK;
-
-#endif
-
-#endif  // KI_MUTEX_H_