Support Reviewing Paste Before Upload

[Nathan Handler]

Often, when uploading a configuration file, users will want to remove any private information (i.e. passwords) before it is uploaded. It would be nice if you could pass an argument to pastebinit that would cause it to launch sensible-editor with the content of the paste displayed. This would allow the user to quickly verify that no sensitive information is going to be uploaded, and provide an opportunity to make quick small changes to the paste content. It would also be nice if you could then abort the paste by exiting the editor without saving (check the file modification time to determine whether it was modified or not).