Added 'xlim' argument to the plotreg function and the coefplot function.

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/texreg@118 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
Removed the vertical.lines argument from plotreg and coefplot and added lwd.zerobar and lwd.vbars instead to make it more flexible.

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/texreg@119 edb9625f-4e0d-4859-8d74-9fd3b1da38cb