Add some extra keybindings

`prelude-smart-open-line` is now bound to `M-o` as well
`prelude-start-open-line-above` is not bound to `M-O` as well
Remove M-O keybinding

It interfered with the Terminal's handling of arrow keys.

This fixes #343.
Map Option to Super and Fn to Hyper

More keybinding options is never a bad thing.
Add prefix arg to prelude-smart-open-line

With a prefix arg the command will invoke prelude-smart-open-line-above
Replace electric-indent-mode and paredit with smartparens
Ops :-)
Remove yasnippets from the list of default packages

Prelude provided just a basic config anyways. Anyone can still install
the package manually and enable it in his/her personal config.
Don't create the snippets dir
Fix some wrong keybindings
Merge pull request #349 from wzpan/readme

Fix some wrong keybindings
Merge remote-tracking branch 'upstream/master'

* upstream/master:
  Fix some wrong keybindings
  Don't create the snippets dir
  Remove yasnippets from the list of default packages
  Ops :-)
  Replace electric-indent-mode and paredit with smartparens
  Add prefix arg to prelude-smart-open-line
  Map Option to Super and Fn to Hyper
  Remove M-O keybinding
  Add some extra keybindings