[thread][circular_buffer] Unmerged changes for 1.62

9 Aug 2016

      Hi,

There are a couple of my PRs hanging for quite some time that I'd like 
to be merged before 1.62 is released:

https://github.com/boostorg/circular_buffer/pull/9

Changes the default implementation of circular_buffer in debug mode to 
the thread-safe by default.

https://github.com/boostorg/thread/pull/92

Fixes compilation of Boost.Thread with MSVC-8.

There is also https://github.com/boostorg/thread/pull/94, which is not 
mine but it looks like it fixes a genuine problem.

Could someone have a look at them and merge? Thanks.

Andrey Semashev