core+main: switch to std::thread and thread_local

Change-Id: I892eb7d87639c2b0d24a8ed457b9d32635269216
diff --git a/wscript b/wscript
index 4722ece..6b7c556 100644
--- a/wscript
+++ b/wscript
@@ -109,7 +109,7 @@
 
     conf.check_cxx(header_name='valgrind/valgrind.h', define_name='HAVE_VALGRIND', mandatory=False)
 
-    boost_libs = ['system', 'program_options', 'filesystem', 'thread']
+    boost_libs = ['system', 'program_options', 'filesystem']
     if conf.env.WITH_TESTS or conf.env.WITH_OTHER_TESTS:
         boost_libs.append('unit_test_framework')