Conver the More Context section into a History section

A history section that provides context :) around the origin and progression of VVV from an internal 10up project to a community organization.
Add an initial CONTRIBUTING document
Move milestones and labels down
Update CHANGELOG with current 1.1 list
Update recommended versions for Vagrant and VirtualBox
Add a link to contributing guidelines in README
Make all contributors links HTTPS

It's like you could tell when GitHub started defaulting to https for everything. Or it's like I typed everything manually before? I don't get it.
Tweak section on WordPress and Vagrant mailing list
Merge pull request #283 from Varying-Vagrant-Vagrants/housekeeping

[PR] Update README, Add initial CONTRIBUTING document
Add Caveats section to readme

Users that are unfamiliar with the project may find some aspects unintuitive.  We should try and warn them so that they can have a better experience 

These are all ways that users broke VVV while I was helping them at WordCamp Lancaster
Alter language a bit in common caveats section
Merge pull request #1 from jeremyfelt/patch-5

Alter language a bit in common caveats section
Merge pull request #291 from aaronjorbin/patch-4

Add Caveats section to readme
Update CHANGELOG with other 1.1 changes
Correct links in previous CHANGELOG notes
Update version to 1.1 in README
Merge pull request #292 from Varying-Vagrant-Vagrants/release-1.1

[PR] Release 1.1
Merge branch 'master' of github.com:Varying-Vagrant-Vagrants/VVV