zsh: cowsay displays cowfiles only.
vim: fix annoying bug

A screen 'shadow' was left on the terminal whenever vim was closed.
zsh: add function plg

Function displays port logfile, useful when authoring ports.
zsh: add error check to cdp

cdp must be called with one and only one argument, the port name one wants
to cd into.
zsh: update submodules
zsh: add perl bindir to path
zsh: aesthetical changes
zsh: fix completion for new port aliases
tmux: add a bunch of options