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
Delete paredit
Merge branch 'master' of https://github.com/bbatsov/prelude into dev
Change yas-snippet-dirs
Fix some wrong keybindings
Merge pull request #349 from wzpan/readme

Fix some wrong keybindings
Move snippets back
Merge remote-tracking branch 'origin/master' into dev
Not too strict about pair balances