vignetted changed to R markdown

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/orgmassspecr@136 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
vignette changed to R markdown

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/orgmassspecr@137 edb9625f-4e0d-4859-8d74-9fd3b1da38cb