Add contribution guidance

Add CONTRIBUTING.md that points to the same document in chef-cookbooks
Add mention of the contribution document in the top of the README.md
Merge pull request #19 from claco/contributing

Merged automatically by jenkins after successful build test
Add Hugh, Andy & Marcelo to the authors
Merge pull request #20 from andymcc/authorz

Add Hugh, Andy & Marcelo to the authors
default !requiretty in sudoers for dsh user

This closes rcbops-cookbooks/swift-private-cloud#40
Merge pull request #21 from rpedde-rcbops/issue-40

Merged automatically by jenkins after successful build test
move user crons to cron.d

partial fix for rcbops-cookbooks/swift-private-cloud#51
Merge pull request #22 from rpedde-rcbops/issue-51

move user crons to cron.d
force memcache to chkconfig on

oddly, the opscode cookbook doesn't appear to :enable memcached.

Fixes rcbops-cookbooks/swift-private-cloud#65
Merge pull request #23 from rpedde-rcbops/issue-65

Merged automatically by jenkins after successful build test