This commit was manufactured by cvs2svn to create branch 'fs_review'.

[SVN r16188]
Preliminary changes after review


[SVN r16291]
many path related review comments applied


[SVN r16394]
directory_iterator simplification


[SVN r16424]
add concept check on iterators


[SVN r16425]
refresh path functionality and names


[SVN r16446]
Initial commit


[SVN r16583]
Final post-review changes


[SVN r16590]