Merge of various bug fixes dealing with mis-detection of BSD on OSX. Fix some documentation typos.

git-svn-id: http://svn.boost.org/svn/boost/branches/release@86315 b8fc166d-592f-0410-95f2-cb63ce0dd405
Merge DateTime bug fix to Release; Fixes #9216

git-svn-id: http://svn.boost.org/svn/boost/branches/release@86322 b8fc166d-592f-0410-95f2-cb63ce0dd405
Minor merging; removing tabs from source files

git-svn-id: http://svn.boost.org/svn/boost/branches/release@86323 b8fc166d-592f-0410-95f2-cb63ce0dd405