Adding support for EWMA to estimate vol for each asset individually for multivariate data

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/uwgarp@148 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
Adding vignette for Monte Carlo methods

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/uwgarp@149 edb9625f-4e0d-4859-8d74-9fd3b1da38cb