Avoid warnings about redefining constants
Avoid warnings about redefining constants

When running under rspec or in daemonized chef-client runs, helper
classes get re-evaluated, leading to warnings since these constants are
already defined. Avoid them by checking defined?

stevendanna/tmux,bitmonk/chef-tmux,bitmonk/chef-tmux,stevendanna/tmux,bitmonk/chef-tmux,stevendanna/tmux