Update ctags options, vim options, function l()

new file:   .ctags
    This is meant for Exuberant Ctags.
    Catch as many c-kinds and c++-kinds automatically.
    Catch locals in Java too.
    (Other defaults sound good.)
modified:   .bash_interactive
    Function l() now uses -lhrt, as in Linux.
modified:   .exrc
    set wrapmargin=4
modified:   .vimrc
    set textwidth=4