Contributor-experienceTM revisited

Hey, the people still read the monodoc mailing list. hehehe, just kidding. I've improved the contributor-experience^TM with a nice dialog to deal with your contributions:

From that dialog you are able to open and remove your contributions and upload the selected ones.

The problem is that contributions made before the patch will not be listed here nor in the root page (however, a message appears at the root page telling you have xx old contribs pending). Also, old contributions will be automatically uploaded with your next upload.

The uploaded contributions are controlled by a serial number (I've realized that was already done after implementing one myself) that acts like an ACK. Every time you upload a contribution, you get a new serial number so new contributions are marked with it and, both, the server and you, know which ones are new contributions and which ones are contributions already uploaded. This way, contributions not being uploaded (not selected) get its serial number updated after a successful upload.

Now, it's time to concentrate in the search thing that I've postponed for a month or so.