Move default command options to its own Proc

First of all, the `CommandSet#default_options` doesn't really belong to
the CommandSet. Secondly, I will use the command options from other
place, but later. Stay tuned!

Signed-off-by: Kyrylo Silin <kyrylosilin@gmail.com>

lib/pry.rb

@@ -130,6 +130,19 @@ class Pry
     end
   end
 
+  Pry::DEFAULT_COMMAND_OPTIONS = proc do |match|
+    {
+      :requires_gem      => [],
+      :keep_retval       => false,
+      :argument_required => false,
+      :interpolate       => true,
+      :shellwords        => true,
+      :listing           => (String === match ? match : match.inspect),
+      :use_prefix        => true,
+      :takes_block       => false
+    }
+  end
+
   # Store the current working directory. This allows show-source etc. to work if
   # your process has changed directory since boot. [Issue #675]
   INITIAL_PWD = Dir.pwd

lib/pry/command_set.rb

@@ -81,7 +81,7 @@ class Pry
     #   # number-N regex command
     def block_command(match, description="No description.", options={}, &block)
       description, options = ["No description.", description] if description.is_a?(Hash)
-      options = default_options(match).merge!(options)
+      options = Pry::DEFAULT_COMMAND_OPTIONS.call(match).merge!(options)
 
       commands[match] = Pry::BlockCommand.subclass(match, description, options, helper_module, &block)
     end
@@ -113,7 +113,7 @@ class Pry
     #
     def create_command(match, description="No description.", options={}, &block)
       description, options = ["No description.", description] if description.is_a?(Hash)
-      options = default_options(match).merge!(options)
+      options = Pry::DEFAULT_COMMAND_OPTIONS.call(match).merge!(options)
 
       commands[match] = Pry::ClassCommand.subclass(match, description, options, helper_module, &block)
       commands[match].class_eval(&block)
@@ -362,21 +362,6 @@ class Pry
         end.map{ |command| command + " " } + Bond::DefaultMission.completions
       end
     end
-
-    private
-
-    def default_options(match)
-      {
-        :requires_gem => [],
-        :keep_retval => false,
-        :argument_required => false,
-        :interpolate => true,
-        :shellwords => true,
-        :listing => (String === match ? match : match.inspect),
-        :use_prefix => true,
-        :takes_block => false
-      }
-    end
   end
 
   # Wraps the return result of process_commands, indicates if the