Fix mkdir on Windows

lfs.mkdir doesn't do the same as teh command line mkdir.


git-svn-id: http://www.latex-project.org/svnroot/experimental/trunk@4763 de43f980-851b-0410-b2f7-c40aca1f87e0
Minore fix for installing README


git-svn-id: http://www.latex-project.org/svnroot/experimental/trunk@4764 de43f980-851b-0410-b2f7-c40aca1f87e0
Switch from "mv" to "ren"

Windows doesn't really like 'move': renaming is an 'in place' operation.


git-svn-id: http://www.latex-project.org/svnroot/experimental/trunk@4765 de43f980-851b-0410-b2f7-c40aca1f87e0