Map a leader key

From http://schlitt.info/opensource/blog/0741_comfortable_php_editing_with_vim_9.html
Commented jj mapping
Added command to show invisible characters

From http://schlitt.info/opensource/blog/0741_comfortable_php_editing_with_vim_9.html
Highlight the current line

From http://schlitt.info/opensource/blog/0741_comfortable_php_editing_with_vim_9.html
Removed mac-specific bash prompt stuff, fixed username