emacs: remove all but basic configuration

no packages, just some look and feel
emacs: add melpa, install use-package
emacs: enable ace-jump-mode using use-package

use use-package to install, load, bind, and configure ace-jump-mode.
emacs: set default indentation

4 spaces, no tabs
emacs: add smart-tabs-mode package

enable for c, c++, and java
emacs: add auto-complete
emacs: add ido and smex
emacs: add undo-tree
emacs: configure whitespace-mode
emacs: add windmove and buffer-move
emacs: add magit
emacs: add keybinding for vc-git-grep
emacs: add ggtags
emacs: add expand-region
emacs: add lua mode
emacs: add android-mode
emacs: open ediff control window in same frame
emacs: add pkgbuild mode
emacs: use dired+ and reuse buffer
emacs: use ibuffer. install ibuffer-vc

rebind buffer-list's keybinding ("C-x C-b") to ibuffer