Thread: provide physical concurrency conditional until it no regression is introduced.

[SVN r85926]
Thread: future::then should join the thread before destruction.

[SVN r85962]
Thread: provide physical_concurrency conditionally.

[SVN r86002]
Thread: update history.

[SVN r86005]
Thread: Remove obsolete GCC version check.

[SVN r86117]
Thread: use boost::disable_if instead of disable_if to avoid ambiguity.

[SVN r86140]
Thread: Added a polymorphic executor and an executor_adaptor.

[SVN r86161]
Thread: try to fix issue with double definition of shared_state_base.

[SVN r86162]
Revert "Thread: provide physical concurrency conditional until it no regression is introduced."

This reverts commit 271ba281aecd5c556b2b863a9f05a8066e717854.

[SVN r86215]
thread: physical_concurrency - work around getline issue in libc++

[SVN r86216]
thread: physical_concurrency - avoid c++03-style vector::data

[SVN r86226]
Thread: Add Copyright.

[SVN r86282]
Thread: Added synchronized_value const test.

[SVN r86283]
Thread: Added future::when_all/when_any (async vector version) for C++11 compilers.

[SVN r86290]
Thread: add thread_pool reserv for worker threads.

[SVN r86291]
Thread: first steps toward async(executor&, f).

[SVN r86327]