added vm setup instructions

    new file:   doc/DEVELOPMENT_SERVER_INSTRUCTIONS.md

I added a "doc" folder with a markdown file with full instructions to set up neurovault_puppet and then NeuroVault.  These are the instructions that worked with virtualbox + vagrant on Ubuntu trusty 64bit - additional OS can be tested and added in the future, if needed.

    modified:   README.md	 

The readme is equivalent, but links to the above file, so the user can find it.