Part of issue #862 - Add beef.debug() for client-side debugging

Add `beef.debug()` function - wraps `console.log()`

Debug messages are suppressed for browsers which don't support `console.log()`

Update './core/*' to use `beef.debug()` instead of `console.log()`
Update './modules/*' to use `beef.debug()` instead of `console.log()`
Update './extensions/*' to use `beef.debug()` instead of `console.log()`

Add 'modules/debug/test_beef_debug/' module

modules/debug/test_beef_debug/module.rb

@@ -0,0 +1,20 @@
+#
+# Copyright (c) 2006-2013 Wade Alcorn - wade@bindshell.net
+# Browser Exploitation Framework (BeEF) - http://beefproject.com
+# See the file 'doc/COPYING' for copying permission
+#
+class Test_beef_debug < BeEF::Core::Command
+
+  def self.options
+    return [
+          {'name' => 'msg', 'description' => 'Debug Message', 'ui_label' => 'Debug Message', 'value' => "Test string for beef.debug() function", 'type' => 'textarea', 'width' => '400px', 'height' => '50px' }
+    ]
+  end
+
+  def post_execute
+    content = {}
+    content['Result'] = @datastore['result']
+    save content
+  end
+
+end