[#722] fix segfault and hung threads on KeyboardIinterrupt during parallel get#728

d-w-moore wants to merge 3 commits intoirods:mainirods/python-irodsclient:mainfrom

d-w-moore:segfault_parallel_io_722.md-w-moore/python-irodsclient:segfault_parallel_io_722.mCopy head branch name to clipboard