adding examples to add.constraint and add.objective

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/returnanalytics@3369 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
fix bug in plot.TimeSeriesFactorModel.r

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/returnanalytics@3370 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
fix a bug in add.up.market.beta in fitTimeSeriesFactorModel.R

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/returnanalytics@3371 edb9625f-4e0d-4859-8d74-9fd3b1da38cb