uses bindler for vagrant plugin management

Squashed commit of the following:

commit 71171546cfc095b30551c99af96b37c3af258574
Author: Conor Schaefer <conor.schaefer@gmail.com>
Date:   Thu Dec 12 12:24:57 2013 -0500

    removes commented out docs in the README

commit 752636935eaa123a7dc6cab4cbeb748da15cf4e2
Author: Conor Schaefer <conor.schaefer@gmail.com>
Date:   Mon Dec 9 16:52:11 2013 -0500

    improves EC2 docs

commit b541bc74d7c7207c6b2e942d93de38ad4dfab246
Author: Conor Schaefer <conor.schaefer@gmail.com>
Date:   Sun Dec 8 21:52:21 2013 -0500

    updates docs with bindler setup info

commit 53db81b71c78f612526f38ca2963ae38d1cd9841
Author: Conor Schaefer <conor.schaefer@gmail.com>
Date:   Sun Dec 8 21:09:50 2013 -0500

    adds plugins.json file for bindler