Added checking for TxnQty and TxnPrice column names


git-svn-id: svn://svn.r-forge.r-project.org/svnroot/blotter@1600 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
Fixed copyright


git-svn-id: svn://svn.r-forge.r-project.org/svnroot/blotter@1601 edb9625f-4e0d-4859-8d74-9fd3b1da38cb