Refactor ido and related packages

* Add package `flx-ido' for fuzzy matching.
* Turn on ido-use-virtual-buffers.
Require common-lisp library
Refactor package `back-button'
Refactor package `highlight-symbol'
Refactor package `paredit'
Refactor package `ack-and-a-half'
Refactor package `auto-complete'
Remove package.el since it is obsolete
Change the keybindings of ace-jump-mode
Add package `paredit-menu'
Move paredit-menu
Refactor package `eshell'
Remove marmalade from package-archives

I found packages on marmalade are often outdated compared with melpa.
Add package `rainbow-delimiters'

* Remove `show-paren-mode' so that the matched parentheses does not get
  highlighted.
* Remove `global-hl-line-mode'. If it is enabled, the words highlighted
  by highlight-symbol-mode on current line become unreadable.
Rewrite aethanyc-keybindings.el by using bind-key
Tweak join-line keybindings
Add package `expand-region'
Add package `rainbow-mode'
Use Dvorak homerow keys to switch window.
Add package `git-gutter-fringe'