coroutine: merge from trunk


[SVN r85163]
coroutine: merge from trunk


[SVN r85320]
coroutine: merge from trunk


[SVN r85377]
coroutine: merge from trunk (documentation)


[SVN r85858]
coroutine: merge from trunk (bufx for export symbols, docu)


[SVN r85981]
coroutine: merge from trunk (fix missing 'inline')


[SVN r85985]
coroutine: fix typo in documentation


[SVN r86342]