Move any? definition to Configuration class

This makes the `any?` method available outside of the DSL module.

lib/capistrano/configuration.rb

@@ -58,6 +58,15 @@ module Capistrano
       return value
     end
 
+    def any?(key)
+      value = fetch(key)
+      if value && value.respond_to?(:any?)
+        value.any?
+      else
+        !fetch(key).nil?
+      end
+    end
+
     def validate(key, &validator)
       vs = (validators[key] || [])
       vs << validator

lib/capistrano/dsl/env.rb

@@ -13,12 +13,7 @@ module Capistrano
       end
 
       def any?(key)
-        value = fetch(key)
-        if value && value.respond_to?(:any?)
-          value.any?
-        else
-          !fetch(key).nil?
-        end
+        env.any?(key)
       end
 
       def roles(*names)