Changed AMM type to lmAMM.

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/eventstudies@225 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
Fixed the code to use lmAMM, fixed reading of extra args for the model, changed code formatting.

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/eventstudies@226 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
minor change in vignette

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/eventstudies@227 edb9625f-4e0d-4859-8d74-9fd3b1da38cb