Added Contribution section to the readme.
Merge pull request #503 from opscode/tc/link-in-contribution

Added Contribution section to the readme.
Add note about chef_max_version bump to 12 to changelog; release notes
Merge branch 'mm/add-version-bump-to-changelog'
erchef version bump
oc_erchef to 27.4; update changelog notes; ldap configuration updates
Merge pull request #499 from opscode/mp/ldap-updates

Mp/ldap updates
expose license settings
Merge pull request #500 from opscode/mp/expose_license_configuration

expose license settings
Updated changelog and release notes for install dir fix.
Also add to 11.*.