Bugfix: Set empty PATH if nil

See https://tickets.opscode.com/browse/CHEF-4358
Bugfix: php-suhosin: check_cmd in subroutine, or it will be executed too early
Bugfix: Moved a line too much in the subroutine
Bugfix: Function in a recipe is not available to a template statmenet
Merge pull request #271 from fh/t/chef-11.10

First fixes for Chef 11.10