Make vSphere scripts work for binary deploys

Fixes #1732.
vSphere capitalization
Update README and getting started guide
Split reactor files

There now are reactor files to run highstate on:

* New nodes only
* Master nodes
* Minion nodes
Rely on ssh-agent for key management
Copy release tars with scp

This displays a progress report, so any slowness can be attributed.
Add 'portal_net' parameter to pillar

In preparation for #1402.
Fix kube-push
Move customizations of /srv/salt to overlay

Also see #1783.
Limit GCE specific mods to GCE
Include cd in getting started guide
Merge pull request #1747 from pietern/vsphere-binary-deploy

vSphere support for binary deploys