Remove redundant "emacs" from package description

From within Emacs it will be clear that this is meant for use in Emacs. :-)
Merge pull request #35 from purcell/patch-1

Remove redundant "emacs" from package description
add melpa doc
Merge branch 'master' into dev
Focus the newly-opened Neotree buffer. Fix #32.
Merge branch 'dev' of github.com:jaypei/emacs-neotree into dev