Merge pull request #3518 from RosettaCommons/roccomoretti/interactive_thread_fixes
Foldit: Fix threading issues found with Clang Thread Sanitizer
Using the Thread Sanitizer from Clang 7, I identified a number of locations where we had potential deadlock issues, as well as some locations where the Thread Sanitizer reported potential data races. This PR doesn't fix all the issues identified by the Thread Sanitizer (there are still some potential race conditions with the sound and the graphics subsystems, and with logging file output, as well as potential issues where I wasn't testing).
Release Note: Fixed latent multithreading bug which resulted in Foldit sometimes hanging.