protect the use of && when BOOST_NO_CXX11_RVALUE_REFERENCES is defined.
Restore breaking change.
don't close the queue when an exception is throw, don't return empty on wait_pull_pull_front.
don't close the queue when an exception is throw, don't return empty on wait_pull_pull_front.
Fix isse on sync_bounded_queue::wait_push_front and add tests.
disable traces.
fix wait_pull_front issue introduced in previous commit and add more tests.
Merge branch 'develop'