Add alias 'E' for sudo-editing with emacsclient

More description available at http://emacs-fu.blogspot.com/2011/12/system-administration-with-emacs.html
Remove redundant arguments and replace 'sudoedit' with 'sudo -e' to be Mac-compatible
Merge pull request #323 from mhsekhavat/alias-emacs-sudoedit

Add alias 'E' for sudo-editing with emacsclient
man -> Dash.app integration for OS X