Add meta key bindings to Emacs, for iTerm support.

ANSI codes from http://stackoverflow.com/questions/10867199/emacs-in-terminal-meta-arrow-keybindings
and http://webframp.com/blog/2013/02/22/fixing-emacs-bindings-on-the-in-iterm2/.
Make Home and End keys work as in CUA.
Vim: Improve CUA-style cut and paste.

Started with the definitions from [http://vim.cybermirror.org/runtime/mswin.vim].
Added functionality when nothing is selected: cut or copy current line.
Fix install script to create symlinks correctly.