Minor change in citation

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/eventstudies@247 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
Changed title and description of the package.

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/eventstudies@248 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
Added details for makeX function

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/eventstudies@249 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
Changed man filename, the package is no longer called eventstudy.

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/eventstudies@250 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
Removed NULL as the default value for firm.returns, its a mandatory argument.

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/eventstudies@251 edb9625f-4e0d-4859-8d74-9fd3b1da38cb