Add vagrant file to bring up webonary dev vm

* Will download a vagrant box with Precise 64, LAMP,
  Zend, and Wordpress with the Webonary plugin
* Box tries to share a folder ../../../sil-dictionary-webonary/trunk
  expecting to find the webonary repository at the same level as
  fwrepo

Change-Id: Icdaa14047b2c8dbd49c150799c6e018de7de2093