SVN: Offload WordPress checkout to the VM

Since the VM has updated SVN, we can completely offload
SVN to it and still have compatible versions between
the host SVN version and the guest.

We should leave the shared plugins in the vip-init script for now
because authentication can still cause issues if you don't
enter the correct username/password when it happens on the VM.
Ideally we can figure out how to do that on the VM in a clean way
as well.
First pass at a CONTRIBUTING file

* Adds the general process for creating an issue and submitting a pull
request
* Adds the directory structure
* Adds some notes about bin scripts, puppet scripts, and WordPress

I don't think this is complete. A FAQ section would probably be nice,
but I haven't received any questions yet. It would be nice to get
some insight into what people want to know.

see #74
Add Minileven checkout

close #69
Merge remote-tracking branch 'upstream/master'
Revert "Checkout mobile themes in Windows"

This reverts commit 7b9ecfb5d2bb1c17d4510203c44021d69555afd6.
Revert "Removing wp-mobile; no longer served that for VIPs"

This reverts commit c50a2860b619e2940dc54fb4202ddf8d74d4f4bd.
Revert "Checkout mobile themes"

This reverts commit 880b98d8b4be60a9cfda275650cf9e2afd24c71c.