made getUnits and S3 generic...

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/rmetrics@5916 5d4a7380-5c0c-0410-b446-d4a5018c0119
made getModel and S3 generic...

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/rmetrics@5917 5d4a7380-5c0c-0410-b446-d4a5018c0119
Made getUnits and getModel work again...
Fixed a bug in getTailRiskBudgets...


git-svn-id: svn://svn.r-forge.r-project.org/svnroot/rmetrics@5918 5d4a7380-5c0c-0410-b446-d4a5018c0119