Use meaningful parameter name in ParseSearchResultFromJson and ParseSearchDatabagFromJson.

Also use static import for Sets and Iterables.
JCLOUDS-285: Add name field in CookbookDefinition domain
Removed unused imports
Make listCookbooksInEnvironment return an empty set on 404

Added tests to validate above.
Also factored out some duplicate code in test.
JCLOUDS-286: Use by default the Omnibus installer