Fix display of deprecated blocks with Sphinx 1.2.
Fix a small CSS glitch with deprecated blocks and Sphinx 1.2.
Closes #14486: add versionchanged notices throughout the threading docs for PEP8-compliant APIs; the note at the top of the page is too hard to notice.
Closes #15829: document ThreadError and fix exception raised for releasing unlocked locks.
Closes #13740: SND_NOWAIT seems to be ignored on modern Windows.
Issue #18739: Fix inconsistent results from math.log(n) and math.log(long(n))