- under windows, modify pathname backslashes to forward slashes

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/pomp@1003 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
- run demos during check even under windows

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/pomp@1004 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
- do not use R --vanilla when doing crancheck

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/pomp@1005 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
- avoid using .Rprofile

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/pomp@1006 edb9625f-4e0d-4859-8d74-9fd3b1da38cb