vim: markdown configuration

Don't hard wrap, check spelling and add mapping to preview.
vim: Portfile snippets

Add mandatory newline after svn id tag.
zsh: fix custom functions

Add shabang, use $0 in usage.
zsh: Move cowsay back to zshrc

zlogin gets executed even if shell is non-interactive.
zsh: don't glob calc
zsh: fix sudo alias
zsh: no need to use different names
zsh: use capital v to invoke editor
zsh: move bindkey stuff to bindkey file
zsh: set extended glob in profile
zsh: move custom completion definitions in separate file
zsh: smarter completions