Add support for Chef Server 11

[nacx]

Add support for Chef Server 11. There are several methods that seem to have changed in the API. It seems that HEAD operations are no longer supported and that cookook upload may have changed. Also the list cookbooks method complains about a duplicate key although the cookbooks are not repeated.

These are the results of the live tests:

Failed tests:   testClientExists(org.jclouds.chef.ChefApiLiveTest): command: HEAD https://10.60.12.7/clients/chef-validator HTTP/1.1 failed with response: HTTP/1.1 405 Method Not Allowed; content: [null]
  testListCookbooks(org.jclouds.chef.ChefApiLiveTest): duplicate key: runit
  testDatabagExists(org.jclouds.chef.ChefApiLiveTest): command: HEAD https://10.60.12.7/data/ibarrera-jcloudstest HTTP/1.1 failed with response: HTTP/1.1 405 Method Not Allowed; content: [null]
  testRoleExists(org.jclouds.chef.ChefApiLiveTest): command: HEAD https://10.60.12.7/roles/ibarrera-jcloudstest HTTP/1.1 failed with response: HTTP/1.1 405 Method Not Allowed; content: [null]
  testDatabagItemExists(org.jclouds.chef.ChefApiLiveTest): command: HEAD https://10.60.12.7/data/ibarrera-jcloudstest/ibarrera-jcloudstest HTTP/1.1 failed with response: HTTP/1.1 405 Method Not Allowed; content: [null]
  testNodeExists(org.jclouds.chef.ChefApiLiveTest): command: HEAD https://10.60.12.7/nodes/ibarrera-jcloudstest HTTP/1.1 failed with response: HTTP/1.1 405 Method Not Allowed; content: [null]
  testCreateNewCookbook(org.jclouds.chef.ChefApiLiveTest): command: PUT https://10.60.12.7/sandboxes/00000000000058b66e27ff217e7852ed HTTP/1.1 failed with response: HTTP/1.1 500 Internal Server Error; content: [internal service error]

Tests run: 53, Failures: 7, Errors: 0, Skipped: 7