Support for naming slicer own threads for debugging.

The following threads are named with this commit:
slic3r_main, slic3r_BackgroundSlicingProcess,
slic3r_tbbpool_xx_yy where xx is a one based index of the TTB thread
and yy is the platform thread ID.

src/libslic3r/Thread.hpp

@@ -0,0 +1,40 @@
+#ifndef GUI_THREAD_HPP
+#define GUI_THREAD_HPP
+
+#include <utility>
+#include <thread>
+#include <boost/thread.hpp>
+
+namespace Slic3r {
+
+void set_thread_name(std::thread &thread, const char *thread_name);
+inline void set_thread_name(std::thread &thread, const std::string &thread_name) { set_thread_name(thread, thread_name.c_str()); }
+void set_thread_name(boost::thread &thread, const char *thread_name);
+inline void set_thread_name(boost::thread &thread, const std::string &thread_name) { set_thread_name(thread, thread_name.c_str()); }
+void set_current_thread_name(const char *thread_name);
+inline void set_current_thread_name(const std::string &thread_name) { set_current_thread_name(thread_name.c_str()); }
+
+// To be called somewhere before the TBB threads are spinned for the first time, to
+// give them names recognizible in the debugger.
+void name_tbb_thread_pool_threads();
+
+template<class Fn>
+inline boost::thread create_thread(boost::thread::attributes &attrs, Fn &&fn)
+{
+    // Duplicating the stack allocation size of Thread Building Block worker
+    // threads of the thread pool: allocate 4MB on a 64bit system, allocate 2MB
+    // on a 32bit system by default.
+    
+    attrs.set_stack_size((sizeof(void*) == 4) ? (2048 * 1024) : (4096 * 1024));
+    return boost::thread{attrs, std::forward<Fn>(fn)};
+}
+
+template<class Fn> inline boost::thread create_thread(Fn &&fn)
+{
+    boost::thread::attributes attrs;
+    return create_thread(attrs, std::forward<Fn>(fn));    
+}
+
+}
+
+#endif // GUI_THREAD_HPP