stabilize build system: depends, installer, boost/bdb fixes, cross targets groundwork

depends/x86_64-pc-linux-gnu/include/boost/signals2/dummy_mutex.hpp

@@ -0,0 +1,28 @@
+// A model of the Lockable concept from Boost.Thread which
+// does nothing.  It can be passed as the Mutex template parameter
+// for a signal, if the user wishes to disable thread-safety
+// (presumably for performance reasons).
+
+// Copyright Frank Mori Hess 2008.
+// Distributed under the Boost Software License, Version
+// 1.0. (See accompanying file LICENSE_1_0.txt or copy at
+// http://www.boost.org/LICENSE_1_0.txt)
+
+// See http://www.boost.org/libs/signals2 for library home page.
+
+#ifndef BOOST_SIGNALS2_DUMMY_MUTEX_HPP
+#define BOOST_SIGNALS2_DUMMY_MUTEX_HPP
+
+namespace boost {
+  namespace signals2 {
+    class dummy_mutex
+    {
+    public:
+      void lock() {}
+      bool try_lock() {return true;}
+      void unlock() {}
+    };
+  } // end namespace signals2
+} // end namespace boost
+
+#endif // BOOST_SIGNALS2_DUMMY_MUTEX_HPP