Ability to work with environments at chef > 0.10.0

I add functionality to work with Environment APIs at chef. 
Next api's calls was implemented:
http://wiki.opscode.com/display/chef/Server+API#ServerAPI-/environments
http://wiki.opscode.com/display/chef/Server+API#ServerAPI-/environments/ENVIRONMENT_NAME
http://wiki.opscode.com/display/chef/Server+API#ServerAPI-/environments/:environment_id/cookbooks
http://wiki.opscode.com/display/chef/Server+API#ServerAPI-/environments/:environment_id/cookbooks/COOKBOOK_NAME

Also search API was updated to support environment search.

org.jclouds.chef.filters.SignedHeaderAuth#filter was updated to be able to  pass "?" to chef-server required by http://wiki.opscode.com/display/chef/Server+API#ServerAPI-/environments/:environment_id/cookbooks (num_versions parameter)