eliminate error log when "enable source maps" is checked under Chrome 29

Under Chrome 29, when "enable source maps" is checked in developer tools settings, the following error logs will be shown in the console, which are annoying:

    Denying load of chrome-extension://bhkcehpnnlgncpnefpanachijmhikocj/include/jquery.min.map. Resources must be listed in the web_accessible_resources manifest key in order to be loaded by pages outside the extension.
    GET chrome-extension://invalid/ 

This commit prevents these error logs from appearing.